spp1786events finalreportsbm0032/spp1786/reports/eventsreport.pdf · in algebraic geometry and...
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SPP 1786 EVENTS
FINAL REPORTS
Final Report. DMV-mini-workshop: “Motivic Homotopy Theory andits application to problems in Algebra and Algebraic Geometry”
The workshop “Motivic Homotopy Theory and its application to prob-lems in Algebra and Algebraic Geometry” took place as part of the DMVyearly meeting in Hamburg, Sept. 22-25, 2015. The workshop itself washeld on Sept. 24, 25. Speakers presented talks on a wide range of subjectsdealing with recent progress in motivic homotopy theory.
The mini-workshop was well-attended, with an average of around 40 inthe audience for the talks.
• Organizers
Philip Herrmann Universitat Hamburg (formerly)Marc Levine Universitat Duisburg-Essen
• Speakers and talks
Speaker Affiliation TitleAlexey Ananyevskiy (Saint Petersburg) Operations in derived
Witt theoryAravind Asok (Los Angeles CA) Algebraizing topological
vector bundlesJean Fasel (Grenoble) Cohomological detection
of complete intersectionsNiko Naumann (Regensburg) Etale descent for
algebraic K-theoryPaul Arne Østvær (Oslo) A1-contractibility of
Koras-Russell threefoldsIvan Panin (Saint Petersburg) Quadratic spaces and
algebraic cobordismsOliver Rondigs (Osnabruck) Algebraic K-theory
of motivic spacesMarkus Spitzweck (Osnabruck) Integral Tate Motives
and Fundamental GroupsMatthias Wendt (Warwick & A1-cobordism and
Duisburg-Essen) A1-weak equivalenceof projective line bundles
For additional information, please see the workshop announcement at theSPP Events page
www.uni-due.de/˜bm0032/SPP1786/Web/SPPevents
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•Use of SPP fundingSPP funds were used for per diem local expenses for the speakers, andhotel costs, travel expenses, conference fees and a conference dinner for thespeakers and organizer.
Expense type Total in ePer diem 700Travel and hotel 5.577Conference fees and dinner 1.214Total 7.491
Final Report. 24th NRW Topology MeetingThe NRW Topology Meetings have been a long-standing fixture of thetopology culture in NRW. The 24th Meeting was held at the Rhein-RuhrUniversitat, Bochum, Nov. 13, 14, 2015.
• OrganizersGerd Laures, Martin Olbermann, Bjorn Schuster and Sebastian Thyssen
• Speakers
Speaker AffiliationTobias Barthel (MPI Bonn)Natalia Castellana (Barcelona)Dustin Clausen (Kopenhagen)Martin Frankland (MPI Bonn)Lennart Meier (Bonn)Martin Olbermann (Bochum)Oliver Rondigs (Osnabruck)Nathaniel Stapleton (MPI Bonn)Kirsten Wickelgren (Georgia)
For further information on the meeting, please see the conference webpage
http://www.ruhr-uni-bochum.de/nrwtop24/.
•Use of SPP fundingFor this meeting, the SPP supported travel and accomodation expensesfor two speakers: Natalia Castellana (Barcelona) and Kirsten Wickelgren(Georgia Institute of Technology).
Expense type Total in eHotel 500Travel 1.550Total 2.050
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FINAL REPORT WORKSHOP“GENERALIZATIONS OF A1-HOMOTOPY INVARIANCE IN
ALGEBRAIC GEOMETRY AND HOMOTOPY THEORY ”
The worshop “Generalizations of A1-Homotopy Invariancein Algebraic Geometry and Homotopy Theory” took placein Zinnowitz/Usedom, from April 3rd to April 8th 2016,with the objective to exchange ideas on A1-invariance in top-ics ranging from constructions of non-A1-invariant motivesand ramification in arithmetic geometry, as well as their re-lation with Arakelov geometry.
http://www.mi.fu-berlin.de/users/esnault/usedom.html
• Organizing Committee
Jose Ignacio Burgos Gil Instituto de Ciencias Matematicas, Madrid, Spainemail: [email protected]://www.icmat.es/miembros/burgos
Helene Esnault Freie Universitat, Berlin, Germanye-mail: [email protected]://www.mi.fu-berlin.de/users/esnault
Moritz Kerz Universitat Regensburg, Germanye-mail: [email protected]://www.mathematik.uni-regensburg.de/kerz/
Jurg Kramer Humboldt Universitat, Berlin, Germanye-mail: [email protected]://www.mathematik.hu-berlin.de/de/personen/prof/1956
Date: April 15, 2016.1
2 REPORT ZINNOWITZ/USEDOM 2016
• Scientific report
Mathematically, the main topics covered by the conference were non-A1-invariant motivic theory, categorial and arithmetic aspects and Arakelovcobordism.
In recent years, lots of developments took place to try to insert very natu-ral non-A1-invariant phenomena in a more general program of motives andmotivic cohomology. On the one hand, one has sheaves like Witt differ-ential forms and algebraic K-theory of singular schemes which are not A1-invariant, on the other hand higher ramification, as opposed to tame ramifi-cation, is not A1-invariant either.
We had lectures on the constructions by Kahn-Saito-Yamazaki of a tri-angulated category of motives, where the ground object is not A1 but a ver-sion of P1 with modulus at infinity. This theory incorporates the classicalRosenlicht reciprocity for morphisms to commutative algebraic groups andshould give a motivic interpretation of the class group with modulus, whichis a central object in algebraic number theory.
We had lectures on Grothendiecks formalism of the six functors withoutA1-invariance, even though the theory is not yet very advanced.
We had lectures on Chow groups with modulus in various shapes and onperverse Nori motives.
On the more arithmetic side we had slightly less talks. Nonetheless welearned about the last developments of exponential motives as initiated byDeligne and Kontsevich, about a version of independence of ` of `-adiccohomology, about Arakelov cobordism groups, and about Gauss-Bhargavatype integrals.
We had several lectures applying methods from abstract homotopy the-ory, for example on a new analytic K-theory of non-archimedean analyticrings and spaces, on the Deligne-Beilinson cohomology spectrum and on anew construction of regulators.
The lectures were of high quality and prolific for all participants.
The feedback we received from participants makes us believe that themeeting was a great success and opened the door to new collaborations.
REPORT ZINNOWITZ/USEDOM 2016 3
• List of participants• Andre, Yves (CNRS-Universite Pierre et Marie Curie-Universite
Paris Diderot)• Asakura, Masanori (Hokkaido University)• Ayoub, Joseph (Universitat Zurich)• Binda, Federico (Universitat Duisburg-Essen)• Bunke, Ulrich (Universitat Regensburg)• Burgos Gil, Jose Ignacio (ICMAT Madrid)• Cisinski, Denis-Charles (Universite Paul Sabatier)• Deglise, Frederic (E.N.S. Lyon-UMPA)• De Jong, Robin (Universiteit Leiden)• Di Proietto, Valentina (FU Berlin)• Esnault, Helene (FU Berlin)• Edixhoven, Sebastiaan Johan ”Bas” (Universiteit Leiden)• Fresan, Javier (ETH Zurich)• Hubner, Katharina (Universitat Heidelberg)• Ivorra, Florian Cedric (Universite de Rennes 1)• Kahn, Bruno (Institut de Mathematiques de Jussieu-Paris Rive Gauche)• Katsigianni, Efstathia (FU Berlin-BMS)• Kaushal, Tanya (FU Berlin-BMS)• Kerz, Moritz (Universitat Regensburg)• Kindler, Lars (FU Berlin)• Krishna, Amalendu (Tata Institute of Fundamental Research)• Langer, Adrian (University of Warsaw)• Lavanda, Elena (FU Berlin-BMS)• Lehalleur, Simon Pepin (FU Berlin)• Levine, Marc (Universitat Duisburg-Essen)• Navarro, Alberto (ICMAT Madrid)• Park, Jinhyun (KAIST)• Pierchalla, Beate (FU Berlin)• Rodriguez, Aurelien (CNRS-Universite Pierre et Marie Curie-Universite
Paris Diderot)• Rlling, Kay (FU Berlin-Heisenberg-Stipendiat DFG)• Sawant, Anand (Universitt Munchen)• Scholbach, Jakob (Westfalische Wilhelms-Universitat Munster)• Saito, Shuji (Tokyo Institute of Technology)• Tamme, Georg (Universitat Regensburg)• Teyssier, Jean-Baptiste (FU Berlin-Hebrew University of Jerusalem)• Unver, Sinan (Koc University)• Yamazaki, Takao (Tohoku University)• Zomervrucht Wouter (FU Berlin-BMS)
4 REPORT ZINNOWITZ/USEDOM 2016
• Schedule
Time Monday Tuesday Wednesday7:45-9:00 Breakfast Breakfast Breakfast
9:00-10:00 Joseph Ayoub Takao Yamazaki Shuji Saito10:00-10:20 Coffee break Coffee break Coffee break10:20-11:20 Bruno Kahn Denis-Charles Cisinski Ulrich Bunke11:40-12:40 Frederic Deglise Jean-Baptiste Teyssier Javier Fresan12:45-14:00 Lunch Lunch Free Afternoon14:30-15:3015:30-16:00 Coffee break Coffee break16:00-17:00 Anand Sawant Bas Edixhoven17:20-18:20 Amalendu Krishna Robin De Jong
Time Thursday Friday7:45-9:00 Breakfast Breakfast
9:00-10:00 Georg Tamme Aurelien Rodriguez10:00-10:20 Coffee break Coffee break10:20-11:20 Federico Binda Kay Rlling11:40-12:40 Jinhyun Park Check out12:45-14:00 Lunch14:30-15:30 Florian Ivorra15:30-16:00 Coffee break16:00-17:00 Simon Pepin Lehalleur17:20-18:20 Jakob Scholbach
REPORT ZINNOWITZ/USEDOM 2016 5
• Titles of the talks
• Joseph Ayoub: On the conservativity conjecture for the Betti reali-sation.• Bruno Kahn: Motives with modulus I (joint work with T. Yamazaki
and S. Saito).• Frederic Deglise: Six functors formalism without A1-invariance.• Anand Sawant: On the affine homotopy invariance of G-torsors.• Amalendu Krishna: Torsion in the zero-cycles with modulus.• Takao Yamazaki: Motives with modulus II (joint work with B. Kahn
and S. Saito).• Denis-Charles Cisinski: Towards a categorical independence of `.• Jean-Baptiste Teyssier: Slopes and periods of connections.• Bas Edixhoven: Gauss composition and primitive integral points on
spheres.• Robin de Jong: Asymptotic behaviour of the heights of bi-extensions.• Shuji Saito: Purity of reciprocity sheaves.• Ulrich Bunke: E∞ version of the Beilinson regulator.• Javier Fresan: Exponential motives.• Georg Tamme: New K-theory of non-archimedean algebras and
spaces.• Federico Binda: Zero cycles on singular varieties and zero cycles
with modulus.• Jinhyun Park: On a multivariate version of additive higher Chow
groups.• Florian Ivorra: Perverse Nori motives and Hodge realization.• Simon Pepin Lehalleur: Triangulated categories of relative 1-motives.• Jakob Scholbach: Modules over the Deligne spectrum.• Aurelien Rodriguez: An Arakelov version of an arithmetic cobor-
dism group.• Kay Rulling: Chow group with modulus and relative Milnor K-
theory.
6 REPORT ZINNOWITZ/USEDOM 2016
• Final Budget
Concept CostAccomodationHousing and meals for all participants at Haus Kranich 11,281.70 eTravel expensesProf. Dr. Yves Andre 58.40 eProf. Dr. Jose Ignacio Burgos Gil 353.25 eDr. Valentina Di Proietto 49.00 eDr. Alberto Navarro Garmendia 446.22 eDr. Florian Ivorra 449.76 eDr. Simon Pepin Lehalleur 43.40 eBeate Pierchalla 198.40 eDr. Kay Rulling 44.80 eDr. Anand Sawant 230.70 eDr. Sinan Unver 104.15 eTotal 13,259.78 e
Mini-workshop report
Title. Motives and derived algebraic geometry
Dates. May 6-8, 2016.
Location. Essen.
Lectures.
Constructibility and continuity in categories of mixed motives. Lec-tures by Denis-Charles Cisinski (Toulouse).
Abstract: These lectures will be an introduction to the theory of mixed motives,after Voevodsky. Although we will focus on motives over classical schemes, we willpresent the constructions and proofs in a way which can be adapted to more generalsettings (algebraic stacks, derived geometry, locally ringed topoi). We will mainlyinsist on various notions of constructibility, from a geometrical and a categoricalpoints of view. Since we will work with motives locally with respect to the taletopology, this will have rather direct interpretations in terms of both intersectiontheory and tale cohomology.
Introduction to spectral algebraic geometry Lectures by David Gepner(Purdue).
Abstract: These lectures will consist of an introduction to the theory of spectralalgebraic geometry, with the goal of stating (and, time permitting, sketching a proofof) Lurie’s generalization of the Artin representability theorem. We will assume fa-miliarity with basic homotopy theory and higher category theory and begin with anaccount of structured infinity-topoi. We will then go on to define spectral schemesand Deligne-Mumford stacks as locally ringed infinity-topoi satisfying certain condi-tions, and discuss how they embed into the big etale topos of the sphere via theirfunctor of points. We will then turn to quasicoherent sheaves, the cotangent com-plex, and deformation theory, leading up to the statement of the representabilitytheorem. The remaining time (if any) will be devoted to applications.
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Schedule.
Friday, 6. May13:30-14:30 Registration14:30-15:30 Cisinski 115:30-16:00 Coffee break16:00-17:00 Gepner 117:15-18:15 Cisinski 2
Saturday, 7. May9:30-10:30 Gepner 210:30-11:00 Coffee break11:00-12:00 Cisinski 312:00-14:00 Lunch14:00-15:00 Gepner 315:15-16:15 Cisinski 416:15-16:45 Coffee break16:45-17:45 Gepner 4
Sunday, 8. May9:30-10:30 Cisinski 510:30-11:00 Coffee break11:00-12:00 Gepner 5
Participants.
Rustam Antia (UT Austin)Benjamin Antieau (University of Illinois at Chicago)Stefano Ariotta (University of Bonn)Peter Arndt (Universitt Regensburg)Tom Bachmann (LMU Mnchen)Eduard Balzin (University of Nice / HSE Moscow)Tobias Barthel (MPI)Falk Beckert (Uni Wuppertal)Pieter Belmans (University of Antwerp)Federico Binda (Universitt Duisburg-Essen)Matt Booth (University of Edinburgh)Clarisson Canlubo (University of Copenhagen)Jin Cao (Universitt Duisburg-Essen)Benjamin Collas (Universitt Bayreuth)Jess Conde Lago (University of Santiago de Compostela)Eivind Dahl (University of Oslo)Elden Elmanto (Northwestern University)Simone Fabbrizzi (University of Bonn)
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Martin Frankland (Universitt Osnabrck)Andrea Gagna (Institut de Mathmatiques de Marseille)Brice Le Grignou (University of Nice)Gabriela Guzman (Universitt Duisburg-Essen)Philip Hackney (Universitt Osnabrck)Daniel Harrer (Universitt Freiburg)Rune Haugseng (University of Copenhagen)Sina Hazratpour (University of Birmingham)Pol van Hoften (University of Utrecht)Andreas Holmstrom (Nordic Math Academy)Fritz Hrmann (Uni Freiburg)Victoria Hoskins (Freie Universitt Berlin)Jonas Irgens (Kylling University of Oslo)Shane Kelly (Universitt Freiburg)Adeel Khan (Universitt Duisburg-Essen)Hoang Kim Nguyen (Uni Regensburg)Hkon Kolderup (University of Oslo)Andrei Konovalov (HSE, Moscow)Markus Land (University of Bonn)Yongqiang Liu (KU Leuven)Nesrin Manav (Gazi University)Lorenzo Mantovani (Universitt Duisburg-Essen)Aaron Mazel-Gee (UC Berkeley)Tasos Moulinos (University of Illinois at Chicago)Toan Nguyen Manh (Universitt Duisburg-Essen)Stefano Nicotra (University of Liverpool)Nina Otter (Mathematical Institute, University of Oxford)Simon Pepin Lehalleur (Freie Universitt Berlin)Marc OlschokAlexander Poddubny (Universitt Osnabrck)Daria Poliakova (HSE Mathematics Department, Moscow)Mauro Porta (IMJ)Marcel Rubi (KU Leuven)Alexander Samokhin (Uni Dsseldorf)Christoph Schrade (University of Regensburg)Vladimir Sosnilo (Saint Petersburg State University)Ismael Souderes (Universitt Osnabrck)Martin Speirs (University of Copenhagen)Markus Spitzweck (Universitt Osnabrck)Jarle Stavnes (University of Oslo)Sean Tilson (Universitt Osnabrck)Niels Uit de Bos (Universitt Duisburg-Essen)Konrad Voelkel (Uni Freiburg)Torstein Vik (Nordic Math Academy)
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Florian Wilsch (Leibniz Universitt Hannover)Maria Yakerson (Universitt Duisburg-Essen)Xuan-Gottfried YangMarcus Zibrowius (Uni Dsseldorf)
Organizers. Peter Arndt (Regensburg) and Adeel Khan (Essen).
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Final Report. Short course: Introduction to unstable motivic homo-topy theoryThis short course on unstable motivic homotopy was held at the Univer-sity of Munster, June 10-12, 2016, with the lectures given by Ben Antieau,Kirsten Wickelgren and Ben Williams. The goal was to give an introductionto the foundations of the theory, to explain the central connectivity result ofMorel and to detail applications of the theory to the study of vector bun-dles on affine varieties. There were problem sessions with accompanying“homework” exercises to help give the participants a better understandingof the material.
• OrganizersName AffiliationRosona Eldred WWU MunsterMarc Levine Univ. Duisburg-EssenMichael Weiss WWU Munster
• SpeakersName Affiliation Lecture SeriesBenjamin Antieau Univ. of Illinois, Applications of unstable
Chicago motivic homotopy theory to theclassification of vector bundle
Benjamin Williams Univ. of British The unstable connectivityColumbia, Vancouver theorem
Kirsten Wickelgren Georgia Inst. of Introduction to unstableTechnology, motivic homotopy theoryAtlanta
• Schedule of Lectures
Friday, June 10Title Speaker TimeApplications of unstable motivic homotopy theory Antieau 11:00-12:00to the classification of vector bundles-Lecture 1Lunch 12:00-2:00Introduction to unstable motivic homotopy theory Wickelgren 2:00-3:00Lecture 1The unstable connectivity theorem-Lecture 1 Williams 3:15-4:15Coffe break 4:15-5:00Problem Session 5:00-6:00
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Saturday, June 11Title Speaker TimeIntroduction to unstable motivic homotopy theory Wickelgren 10:00-11:00Lecture 2Introduction to unstable motivic homotopy theory Wickelgren 11:15-12:15Lecture 3Lunch 12:15-2:00The unstable connectivity theorem-Lecture 2 Williams 2:00-3:00Applications of unstable motivic homotopy theory Antieau 3:15-4:15to the classification of vector bundles-Lecture 2Coffee break 4:15-5:00Problem Session 5:00-6:00Sunday, June 12Title Speaker TimeThe unstable connectivity theorem-Lecture 3 Williams 10:00-11:00Applications of unstable motivic homotopy theory Antieau 11:15-12:15to the classification of vector bundles-Lecture 3
• Participants
Name AffiliationElie Alhajjar George Mason UniversityOliver Anderson University of LiverpoolDinesh Bhattarai Liberty Institute of TechnologyFederico Binda Univ. Duisburg-EssenJin Cao Univ. Duisburg-EssenJoana Cirici WWU MunsterBenjamin Collas Univ. BayreuthRosona Eldred WWU MunsterElden Elmanto Northwestern UniversityGabriela Guzman Univ. Duisburg-EssenGeoffroy Horel MPIM, BonnAdeel Khan Univ. Duisburg-EssenViktor Kleen USCMarc Levine Univ. Duisburg-EssenMy Ismail Mamouni CRMEF Rabat, MoroccoLorenzo Mantovani Univ. Duisburg-EssenPatrick McFaddin Univ. of GeorgiaManh Toan Nguyen Univ. Duisburg-Essen
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Name AffiliationStefano Nicotra Univ. of LiverpoolJames Plowman Univ. of WarwickDavid Sabonis TU MunchenAlexander Samokhin HHU DusseldorfHusney Parvez Sarwar TIFR, MumbaiDivya Sharma WWU MunsterAngelica Simonetti U. Mass., AmherstVladimir Sosnilo Univ. Duisburg-EssenTariq Syed LMU MunchenSabrina Syed Univ. OsnabruckMichael Weiss WWU MunsterHeng Xie Univ. of WarwickSerge Yagunov Steklov Math. Inst.,St.-PetersburgMaria Yakerson Univ. Duisburg-EssenXuan-Gottfried Yang Independent researcherFerdinando Zanchetta Univ. of WarwickMasoud Zargar Princeton
For further information on the meeting, please see the conference webpage
www.esaga.uni-due.de/marc.levine/IntroHtpyThyMunster2016/.
•Use of SPP fundingFor this meeting, the SPP supported hotel and travel expenses for the speak-ers and 1 organizer (Levine), as well as for selected participants. Additionalfunds were used for coffee and office material.
Expense type Total in eHotel 5.055Travel 4.394Misc. 98Total 9.547
WORKSHOP: MOTIVIC HOMOTOPY GROUPS OF SPHERES II
This workshop funded by the SPP 1786 took place June 21 – 25, 2016, at the UniversitatDuisburg-Essen (Campus Essen). The workshop was organised by Aravind Asok (USC), MarcLevine (Universitat Duisburg-Essen) and Oliver Rondigs (Universitat Osnabruck). As the titlealready suggests, the workshop was the second in a series; the first one took place June , 2014,again at the Universitat Duisburg-Essen (Campus Essen), and the third one will take placeJune 25 – 29, 2018, at the Freie Universitat Berlin. This series treats a topic at the center ofthe Schwerpunktprogramm 1786 “Homotopy theory and algebraic geometry”: The homotopy-theoretic understanding of motivic spheres (objects associated with punctured affine spacesover a base scheme) and implications in algebraic geometry. While the emphasis on youngspeakers is explained by the attractivity and freshness of the subject, several talks were givenby well-established mathematicians high international recognition. Besides the high quality ofthe presentations, one of its successes was to provide ample space for discussions, in order tostimulate future work and collaborations.
• Speakers
Name Current Affiliation
Alexey Ananyevskiy (Steklov Institute, St. Petersburg)Tom Bachmann (Universitat Duisburg-Essen)Jean Fasel (Universite de Grenoble)Bertrand Guillou (University of Kentucky)Jeremiah Heller (University of Illinois at Urbana-Champaign)Jens Hornbostel (Bergische Universitat Wuppertal)Marc Hoyois (USC)Paul Arne Østvær (Oslo University)Kyle Ormsby (Reed College)Ivan Panin (Steklov Institute, St. Petersburg)Anand Sawant (LMU Munchen)Marco Schlichting (University of Warwick)Markus Spitzweck (Universitat Osnabruck)Burt Totaro (UCLA)Kirsten Wickelgren (Georgia Tech)Benedict Williams (UBC)
The schedule was at follows:
June 21 June 22 June 23 June 24 June 259:30 Hornbostel Bachmann Østvær Ananyevskiy Schlichting10:30 Registration Coffee Coffee Coffee Coffee11:00 Spitzweck Panin Sawant Williams Ormsby12:00 Lunch Lunch Lunch Lunch Lunch14:30 Totaro Fasel Discussions Hoyois15:30 Coffee Coffee Coffee16:00 Heller Wickelgren Guillou19:00 Dinner
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• Participants
Name Affiliation
Peter Arndt Uni DsseldorfAravind Asok USCTom Bachmann LMU MunichFalk Beckert Univ. WuppertalPrasit Bhattacharya Notre DameFederico Binda Univ. Duisburg-EssenYue Feng Yau Tsinghua UniversityMartin Frankland Univ. OsnabruckBogdan Gheorghe Wayne State UniversityJonas Irgens Kylling University of OsloWataru Kai Tokyo Univ.Viktor Kleen USCSanaa Madad Univ. Hassan II MoroccoLorenzo Mantovani Univ. Duisburg-EssenNiko Naumann Univ. RegensburgAlberto Navarro icmatManh Toan Nguyen Univ. Duisburg-EssenJoseph Rabinoff Georgia TechOliver Roendigs Univ. OsnabruckDavid Sabonis TU MunichAnand Sawant LMU MunichAlexander Schmitt FU BerlinSean Tilson Univ. OsnabruckIsmael Souderes Univ. OsnabruckSven-Torben Stahn Univ. WuppertalManfred Stelzer Univ. OsnabruckFlorian Strunk Univ. RegensburgGirja Tripathi Univer. OsnabruckGlen Wilson Rutgers University,
Univ. OsloHeng Xie Univ. WarwickMasoud Zargar Princeton
• Use of SPP funding
SPP funds were used for hotel accomodation and travel expenses for speakers, and additionalfunds for the coffee and snacks between lectures. We also supported travel expenses and/orhotel expenses for seven selected junior participants.
Expense type Total in e
Hotel 18.244Travel 13.026Coffee breaks 240Total 31.510
Further details on the workshop, such as abstracts, can be found at the webpage:
https://sites.google.com/site/motivichomotopyofspheresii/
WORKSHOP: WOMEN IN HOMOTOPY THEORY AND ALGEBRAIC
GEOMETRY
This workshop funded by the SPP 1786 took place from the 13 - 15 September 2016 at theFreie Universitat Berlin; the workshop was organised by Joana Cirici (previously FU Berlin,now Universitat Munster), Victoria Hoskins (FU Berlin) and Oliver Rondigs (Universitat Os-nabruck). The workshop was dedicated to the promotion of female researchers in the field ofhomotopy theory and algebraic geometry. The main aim of the workshop was to provide aplatform for female researchers, ranging from graduate students to senior experts, to presenttheir work in a friendly environment which stimulates future collaborations.
The scientific contributions to the workshop were all given by female participants and wereas follows.
• Invited talks: Helene Esnault (FU Berlin), Donatella Iacono (Universita degli studi diBari), Birgit Richter (Universitat Hamburg), Ulrike Tillmann (University of Oxford).
• Contributed talks: Daniela Egas Santander (FU Berlin), Rosona Eldred (Universityof Munster/HIM Bonn), Sara Angela Filippini (Aix-Marseille Universite), MagdalenaKedziorek (EPFL), Elena Lavanda (FU Berlin), Elena Martinengo (Leibniz UniversitatHannover), Mariko Ohara (Shinshu University), Viktoriya Ozornova (Universitat Bonn),Rekha Santhanam (IIT Bombay), Stephanie Ziegenhagen (KTH Stockholm).
• Poster presentations: Lauren Bandklayder, Cameron Crowe, Eugenia Ellis, ElisaHartmann, Inbar Klang, Aradhana Kumari, Eva Martınez, Irem Portakal, AlejandraRincon, Anna-Laura Sattelberger, Julia Schulz.
Additionally we organised a discussion session to address topics and issues facing women inmathematics, and to discuss career and funding opportunities for women.
The workshop had 36 registered participants: Lauren Bandklayder, Dominic Bunnett, JoanaCirici, Cameron Crowe, Daniela Egas Santander, Rosona Eldred, Eugenia Ellis, Helene Es-nault, Barbara Fantechi, Sara Angela Filippini, Hamza Foudali, Elisa Hartmann, Eva Honing,Victoria Hoskins, Donatella Iacono, Magdalena Kedziorek, Inbar Klang, Elena Lavanda, ElenaMartinengo, Eva Martınez, Mariko Ohara, Viktoriya Ozornova, Simon Pepin Lehalleur, IremPortakal, Birgit Richter, Alejandra Rincon, Oliver Rondigs, Rekha Santhanam, Anna-LauraSattelberger, Caren Schinko, Julia Schulz, Irene Schwarz, Sabrina Syed, Ulrike Tillmann, Vin-cent Trageser, Stephanie Ziegenhagen.
The funding from the SPP 1786 was spent as follows:
• 3784,40 Euros on accommodation for 3 invited speakers, 7 contributed speakers and 11young participants.
• 6848,77 Euros on travel for 3 invited speakers, 8 contributed speakers and 10 youngparticipants.
• 300,00 Euros on honoraria for 3 invited speakers.• 168,43 Euros on coffee breaks.• 173,40 Euros on funding dinner for all the speakers.• 39,00 Euros on conference materials.
This adds up to a total budget of 11315 Euros.The workshop was very well received by the participants. Certainly the high quality of the
presentations contributed to its success. The invited speakers, being leading experts in theirrespective fields of highest esteem, fulfilled several functions (scientific and career advice, rolemodel), while the contributed talks and poster presentations allowed younger researchers tonot only present their work, but also interact on an informal level. Also the discussion sessioncontained plenty of valuable and helpful exchanges, which should also assist in preparing andorganising a second workshop of this kind. Despite explicit invitations, only very few established
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male researchers were present. A further installment of this workshop would put even moreefforts into attracting more researchers (male or female) who act decisively in hiring processes.
Further details on the workshop can be found at the webpage:
userpage.fu-berlin.de/jcirici/workshop.html
SPP Workshop “Differential forms in algebraicgeometry” final report
About the workshopThe aim of this workshop is to bring experts from the field of motives
together with specialists in birational geometry and algebraic geometry inpositive characteristic.
Final budget (Summary)Priority Program: 8258 EurSFB Mainz: 3312,13 EurGRK Freiburg: 720 EurMath Department Freiburg (DFG Overhead): 1931,63 Eur
List of speakers
(1) Daniel Greb, Universitat Duisburg-Essen(2) Florian Ivorra, Universite Rennes 1(3) Sandor Kovacs, University of Washington(4) Kay Rulling, FU Berlin(5) Karl Schwede, University of Utah(6) Joseph Ayoub, Universitat Zurich(7) Jean-Louis Colliot-Thelene, CNRS/Universite Paris-Sud(8) Zsolt Patakfalvi, Princeton and EPFL Lausanne(9) Joseph Steenbrink, Radboud Universiteit
(10) Yohan Brunebarbe, EPFL Lausanne/Zurich(11) Shunsuke Takagi, Tokyo(12) Arne Smeets, Imperial College(13) Takao Yamazaki, Tohoku(14) Helene Esnault, FU Berlin(15) Adrian Langer, Warsaw
List of participants
(1) Federico Binda, University of Duisburg-Essen, Germany(2) Daniel Greb, University of Duisburg-Essen, Germany(3) Lorenzo Mantovani, University of Duisburg-Essen, Germany(4) Jean-Louis Colliot-Thelene, CNRS/University of Paris-Sud, France(5) Remy van Dobben de Bruyn, Columbia University in the City of
New York(6) Yohan Brunebarbe, EPFL Lausanne/Zurich, Switzerland
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(7) Helene Esnault, Free University of Berlin, Germany(8) Simon Pepin Lehalleur, Free University of Berlin, Germany(9) Marta Pieropan, Free University of Berlin, Germany
(10) Kay Rulling, Free University of Berlin, Germany(11) Fabio Bernasconi, Imperial College London, UK(12) Arne Smeets, Imperial College London, UK(13) Masaaki Murakami, Kagoshima University, Japan(14) Soudabeh Dalvandi, Karaj Islamic Azad University, Iran(15) Mirko Mauri, London School of Geometry and Number Theory, UK(16) Enrica Mazzon, London School of GeometryandNumberTheory, UK(17) Thomasz Szemberg, Pedagogical University of Cracow, Poland(18) Justyna Szpond, Pedagogical University of Cracow, Poland(19) Zsolt Patakfalvi, Princeton and EPFL Lausanne(20) Yuchen Liu, Princeton University (USA)(21) Charlie Stibitz, Princeton University (USA)(22) Joseph Steenbrink, Radboud University Nijmegen, Netherlands(23) Takao Yamazaki, Tohoku University, Japan(24) Taro Fujisawa, Tokyo Denki University, Japan(25) Atsushi Ikeda, Tokyo Denki University, Japan(26) Rin Sugiyama, Tokyo Denki University, Japan(27) Lance Edward Miller, University of Arkansas (USA)(28) Andrea Fanelli, University of Basel, Switzerland(29) Patrick Graf, University of Bayreuth, Germany(30) Roberto Svaldi, University of Cambridge, UK(31) Joe Waldron, University of Cambridge, UK(32) Gabriela Guzman, University of Duisburg-Essen, Germany(33) Stefan Heuver, University of Duisburg-Essen, Germany(34) Mihir Sheth, University of Duisburg-Essen, Germany(35) Hannah Bergner, University of Freiburg, Germany(36) Florian Beck, University of Freiburg, Germany(37) Oliver Braunling, University of Freiburg, Germany(38) Daniel Harrer, University of Freiburg, Germany(39) Annette Huber-Klawitter, University of Freiburg, Germany(40) Stefan Kebekus, University of Freiburg, Germany(41) Shane Kelly, University of Freiburg, Germany(42) Matthias Kositzki, University of Freiburg, Germany(43) Rene Recktenwald, University of Freiburg, Germany(44) Martin Schwald, University of Freiburg, Germany(45) Wolfgang Soergel, University of Freiburg, Germany(46) Elmiro Vetere, University of Freiburg, Germany(47) Giovanni Zaccanelli, University of Freiburg, Germany(48) Giulia Battiston, University of Heidelberg, Germany(49) Kevin Tucker, University of Illinois at Chicago (USA)(50) Manuel Blickle, University of Mainz, Germany(51) Simon Felten, University of Mainz, Germany
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(52) Ariyan Javanpeykar, University of Mainz, Germany(53) Juanita Gatt, University of Malta(54) Helmut A. Hamm, University of Munster, Germany(55) Veronika Ertl, University of Regensburg, Germany(56) Florian Ivorra, University of Rennes 1, France(57) Julien Sebag, University of Rennes 1, France(58) Valeria Bertini, University of Strasbourg, France(59) Shunsuke Takagi, University of Tokyo, Japan(60) Karl Schwede, University of Utah (USA)(61) Adrian Langer, University of Warsaw, Poland(62) Maciek Zdanowicz, University of Warsaw, Poland(63) Sandor Kovacs, University of Washington (USA)(64) Joseph Ayoub, University of Zurich, Switzerland
REPORT ON THE WORKSHOP: HERMITIAN K-THEORY AND TRACEMETHODS
ORGANIZERS: EMANUELE DOTTO, AMALIE HØGENHAVEN, KRISTIAN JONSSON MOI, IRAKLIPATCHKORIA
In recent years there has been a lot of research activity around Hermitian K-theory asdefined by Karoubi, Schlichting and Hornbostel, and its relations to K-theory and topologicalhochschild homology. In 2012 Hesselholt and Madsen introduced real algebraic K-theory KRwhich is a genuine C2-equivariant spectrum whose underlying spectrum is Quillen’s algebraicK-theory and whose C2-fixed points are Hermitian K-theory. Many structural results havebeen proven for Hermitian K-theory and KR including group completion, additivity andlocalization theorems (proved by Hesselholt and Madsen, Moi, Schlichting) and connectionsto L-theory (Schlichting). Dotto and Hesselholt-Madsen have also extended trace methods toreal algebraic K-theory. On the other hand Hermitian K-theory plays an important role inmotivic homotopy theory and motivic methods have been used to study it, e.g. by Hornbosteland Østvær-Röndigs-Spitzweck. The main aim of the workshop was to bring people working onHermitian K-theory from different perspectives together and to discuss connections betweenthese perspectives.
The workshop “Hermitian K-theory and trace methods” took place at Hausdorff ResearchInstitute for Mathematics (HIM) in Bonn from November 7th to November 11th 2016. It hadaround 70 participants (including around 30 people who were visiting the HIM for the JuniorTrimester Program in Topology). The workshop was part of the Junior Trimester Program inTopology. The workshop also incorporated the Felix-Klein lectures by Lars Hesselholt at theHIM.
The workshop consisted of four mini-courses and several single lectures. Lars Hesselholttalked about periodic topological cyclic homology and its connections to number theory andregularized determinants. He also discussed the construction of real algebraic K-theory andthe proof of additivity theorem for KR. Marco Schlichting talked about higher Grothendieck-Witt groups. Bjørn Dundas gave an overview of Topological Hochschild homology and usingtrace maps for K-theory computations. Finally, Oliver Röndigs discussed slices of HermitianK-theory in the context of motivic homotopy theory.
The single lectures were given by Alon Nissan-Cohen, Jens Hornbostel, Markus Land,Markus Spitzweck, Marco Varisco and Paul Arne Østvær. Nissan-Cohen talked about infinitycategorical interpretation of real Topological Hochschild homology. Hornbostel talked aboutthe motivic Hopf map and its connection to Witt groups. Land talked about L-theory spectraand topological K-theory spectra for C∗-algebras. Spitzweck presented an infinity categori-cal approach to the real algebraic K-theory. Varisco discussed assembly maps for Topologicalcyclic homology and Østvær talked about the homotopy limit problem in Hermitian K-theory.
Overall the workshop was a success. The feedback given on the evaluation forms wasvery positive, there were many lively discussions and several participants have started newcollaborations after the workshop.
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Schedule of the Workshop "Hermitian K-theoryand trace methods"
Monday, November 710:30 - 11:00 Registration & Welcome coffee11:00 - 12:00 Marco Schlichting: Introduction to Higher Grothendieck-Witt groups (Lecture 1)12:00 - 13:50 Lunch break13:50 - 14:50 Bjørn Dundas: The trace map15:00 - 16:00 Markus Land: The 2-completion of L-theory for C*-algebras16:00 - 16:30 Tea and cake16:30 - 17:30 Discussionafterwards Reception
Tuesday, November 810:00 - 10:45 Lars Hesselholt: Around topological Hochschild homology (Lecture 1)10:45 - 11:15 Group photo and coffee break11:15 - 12:00 Lars Hesselholt: Around topological Hochschild homology (Lecture 2)12:00 - 13:50 Lunch break13:50 - 14:50 Marco Schlichting: Introduction to Higher Grothendieck-Witt groups (Lecture 2)
15:00 - 16:00Marco Varisco: Assembly maps for topological cyclic homology and related theories
16:00 - 16:30 Tea and cake
Wednesday, November 909:30 - 10:30 Marco Schlichting: Introduction to Higher Grothendieck-Witt groups (Lecture 3)10:30 - 11:00 Coffee break11:00 - 12:00 Alon Nissan-Cohen: Towards an ∞-categorical version of real THH12:00 - 13:50 Lunch break13:50 - 14:50 Bjørn Dundas: Consequences for K-theory15:00 - 16:00 Oliver Röndigs: The slices of Hermitian K-theory (Lecture 1)16:00 - 16:30 Tea and cake19:00 - Conference dinner in the Restaurant Meyer's (Clemens-August-Str. 51a)
Thursday, November 1009:30 - 10:30
Paul Arne Østvær: The motivic Hopf map and the homotopy limit problem for (hermitian) K-theory
10:30 - 11:00
Coffee break
11:00 - 12:00
Jens Hornbostel: Non-nilpotent motivic self maps and Witt groups
12:00 - 13:50
Lunch break
13:50 - 14:50
Oliver Röndigs: The slices of Hermitian K-theory (Lecture 2)
15:00 - 16:00
Markus Spitzweck: A Grothendieck-Witt space for stable infinity categories with duality
16:00 - 16:30
Tea and cake
Friday, November 1110:00 - 10:45 Lars Hesselholt: Around topological Hochschild homology (Lecture 3)10:45 - 11:15 Coffee break11:15 - 12:00 Lars Hesselholt: Around topological Hochschild homology (Lecture 4)12:00 - Lunch break, end of workshop
List of speakers
Mini-course speakers:
Marco Schlichting, Professor, University of Warwick, UK
Lars Hesselholt, Professor, Copenhagen University, Denmark
Bjorn Dundas, Professor, University of Bergen, Norway
Oliver Roendigs, Professor, Universität Osnabrück, Germany
Regular speakers:
Markus Land, Postdoc, Universität Regensburg, Germany
Markus Spitzweck, Professor, Universität Osnabrück, Germany
Paul Arne Ostvaer, Professor, Univerity of Oslo, Norway
Jens Hornbostel, Professor, Bergische Universität Wuppertal, Germany
Alon Nissan-Cohen, PhD student, Hebrew University of Jerusalem, Israel
Marco Varisco, Professor, University of Albany, SUNY, USA
Participants of the Workshop "Hermitian K-theory and trace methods"The list below includes the workshop participants as well as the participants of the Junior Trimester Program who are at the Institute during the workshop.
Name Affiliation Period of stayPeter Arndt Universität Düsseldorf
Anandam BanerjeeIndian Institute of Science Education and Research Mohali
07.11.2016 – 11.11.2016
Tobias Barthel University of Copenhagen
Stefan Behrens Universiteit Utrecht07.11.2016 – 11.11.2016
Pedro Boavida de Brito University of Lisbon12.09.2016 – 19.12.2016
Lukas Brantner Harvard University01.11.2016 – 10.11.2016
Tyrone Crisp MPIM
Christopher Davis The University of Wisconsin - Eau Claire05.09.2016 – 22.12.2016
Emanuele Dotto Massachusetts Institute of Technology05.09.2016 – 22.12.2016
Bjorn Ian Dundas University of Bergen06.11.2016 – 10.11.2016
Rosona Eldred Universität Münster26.09.2016 – 22.12.2016
Martin Frankland Universität Osnabrück
Daniel Grech University of Warwick06.11.2016 – 11.11.2016
Philip Hackney Macquarie University / MPIM Drew Heard Universität Hamburg Lars Hesselholt University of Copenhagen
Gijs Heuts Copenhagen University02.10.2016 – 03.12.2016
Geoffroy Horel MPIM12.09.2016 – 22.12.2016
Asaf Horev The Hebrew University of Jerusalem Ryo Horiuchi University of Copenhagen
Jens Hornbostel Bergische Universität Wuppertal07.11.2016 – 11.11.2016
Anders Husebø Universitetet i Bergen06.11.2016 – 15.11.2016
Name Affiliation Period of stay
Amalie Høgenhaven University of Copenhagen06.11.2016 – 22.11.2016
Artur Jackson Purdue University
Holger Kammeyer Karlsruher Institut für Technologie05.09.2016 – 22.12.2016
Aditi Kar University of Southampton03.10.2016 – 30.11.2016
Daniel Kasprowski MPIM05.09.2016 – 22.12.2016
Min Hoon Kim Korea Institute for Advanced Study (KIAS)02.09.2016 – 22.12.2016
Steffen Kionke Heinrich-Heine-Universität Düsseldorf05.09.2016 – 22.12.2016
Arun Kumar Universität Osnabrück06.11.2016 – 11.11.2016
Alexander Kupers Københavns Universitet07.11.2016 – 11.11.2016
Malte Lackmann Universität Bonn
Markus Land Universität Regensburg06.11.2016 – 12.11.2016
Filipp Levikov Freie Universität Berlin
Alejo Lopez-Avila Universität Osnabrück06.11.2016 – 11.11.2016
Akhil Mathew Harvard University02.10.2016 – 03.12.2016
Duncan McCoy University of Glasgow03.10.2016 – 26.11.2016
Jeffrey Meier Indiana University05.09.2016 – 22.12.2016
Lennart Meier Universität Bonn02.10.2016 – 03.12.2016
Allison Miller University of Texas, Austin05.09.2016 – 22.12.2016
Kristian Jonsson Moi WWU Münster01.09.2016 – 22.12.2016
Matthias Nagel Université du Québec à Montréal05.09.2016 – 22.12.2016
Manh Toan Nguyen Universität Osnabrück Espen Auseth Nielsen University of Copenhagen Alon Nissan-Cohen The Hebrew University of Jerusalem Asbjørn Christian Nordentoft
University of Copenhagen
Name Affiliation Period of stay
Patrick Orson University of Durham29.10.2016 – 18.12.2016
Paul Arne Ostvaer University of Oslo06.11.2016 – 12.11.2016
Byung Do Park MPIM
Jung Hwan Park Rice University02.09.2016 – 22.12.2016
Irakli Patchkoria Universität Bonn19.09.2016 – 22.12.2016
Malte Pieper Universität Bonn
Mark Powell Université du Québec à Montréal01.09.2016 – 24.12.2016
Matthew Pressland MPIM
Jean Raimbault Université Paul Sabatier05.09.2016 – 16.12.2016
Arunima Ray Brandeis University27.08.2016 – 23.12.2016
Sune Precht Reeh Massachusetts Institute of Technology27.08.2016 – 22.12.2016
Marcy Robertson University of Melbourne05.09.2016 – 22.12.2016
Oliver Roendigs Universität Osnabrück07.11.2016 – 11.11.2016
Alexander Samokhin Heinrich-Heine-Universität Düsseldorf
Tomer Schlank The Hebrew University of Jerusalem31.10.2016 – 12.11.2016
Marco Schlichting University of Warwick06.11.2016 – 09.11.2016
Olaf Schnürer Universität Bonn Stefan Schwede Universität Bonn Martin Speirs University of Copenhagen
Markus Spitzweck Universität Osnabrück06.11.2016 – 12.11.2016
Florian Strunk Universität Regensburg Yuri Sulyma University of Texas at Austin
Mark Ullmann Freie Universität Berlin03.09.2016 – 23.12.2016
Marco Varisco University at Albany, SUNY06.11.2016 – 11.11.2016
Paula Verdugo Universität Osnabrück06.11.2016 – 11.11.2016
Christoph Winges WWU Münster 05.09.2016 –
Name Affiliation Period of stay22.12.2016
Tian An Wong MPIM
Jianchao Wu Penn State University16.10.2016 – 20.11.2016
Maria Yakerson Universität Duisburg-Essen07.11.2016 – 10.11.2016
Ferdinando Zanchetta University of Warwick06.11.2016 – 11.11.2016
Marcus Zibrowius Heinrich-Heine-Universität Düsseldorf
Final Report. SPP 1786 Jahrestagung 2017We held the first SPP Jahrestagung in Wuppertal, March 21-24 2017. Thename is a misnomer, as we decided to hold our global SPP meeting everytwo years. The idea behind the meeting was to have a mixture of talks fromwithin the SPP network as well having some talks by recognized expertsfrom outside the network. The conference attracted quite a bit of attentionboth within and outside the SPP network. The talks dealt with a interestingmix of topics including: classical theory of motives, homotopy theory ofring spectra, motivic theories for derived schemes, global homotopy theory,cohomological invariants of algebraic groups, and constructions in equivari-ant homotopy theory.
• OrganizersName AffiliationJens Hornbostel Univ. WuppertalMarc Levine Univ. Duisburg-Essen
• SpeakersName Affiliation Lecture TitleFederico Binda Univ. Regensburg Towards a motivic homotopy
theory without A1-invarianceJoana Cirici Univ. Munster Formality of symmetric
monoidal functors andoperads via mixedHodge theory
Benjamin Collas Univ. Bayreuth Moduli stack of curvesand motivic homotopy
John Greenlees Univ. of Sheffield The Balmer spectrum of thecategory of rational equi-variant cohomology theories
Markus Hausmann Univ. Copenhagen Symmetric products andsubgroup lattices
Thomas Hudson Univ. Wuppertal Segre classes for algebraiccobordism and their appli-cation to Schubert calculus
Moritz Kerz Univ. Regensburg Algebraic K-theory anddescent for blow-ups
Adeel Khan Univer. Regensburg Homotopy K-theory ofE∞-ring spectra
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Name Affiliation Lecture TitleLennart Meier Univ. Bonn Real spectra and their dualsIrakli Patchkoria Univ. Bonn Proper equivariant
stable homotopy theorySimon Pepin-Lehalleur FU Berlin Constructible 1-motivesSteffen Sagave Radboud University Logarithmic topological
Hochschild homologyStefan Schwede Univ. Bonn Global homotopy theoryNikita Semenov LMU Munchen Cohomological invariants
of algebraic groups andthe Morava K-theory
Vesna Stojanoska UIUC The Gross-Hopkins duals ofhigher real K-theory spectra
Marcus Zibrowius Univ. Dusseldorf The symmetric complexover projective space
• Participants
Name AffiliationYassine Amri Hassan II UniversityPeter Arndt Univ. DusseldorfFalk Beckert Univ. WuppertalFederico Binda Univ. RegensburgThomas Bryan Univ. WuppertalJose Gabriel Carrasquel Vera Univ. PoznanGeorgios Charalambous Univ. of CambridgeJoana Cirici WWU-MunsterBenjamin Collas Univ. BayreuthChristian Dahlhausen Univ. RegensburgYue Feng Tsinghua UniversityMartin Frankland Univ. OsnabruckGrigory Garkusha Swansea UniversityJohn Greenlees Sheffield UniversityJohann Haas Univ. RegensburgDrew Heard Univ. HamburgJens Hornbostel Univ. WuppertalVictoria Hoskins FU BerlinMoritz Kerz Univ. RegensburgAdeel Khan Univ. RegensburgAlexander Korschgen Univ. Bonn
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Name AffiliationAndrei Lavrenov LMU MunchenMarc Levine Univ. Duisburg-EssenFosco Loregian UWOLorenzo Mantovani Univ. Duisburg-EssenLennart Meier Univ. BonnViktoriya Ozornova Univ. BonnIrakli Patchkoria Univ. BonnSimon Pepin Lehalleur FU BerlinBirgit Richter Univ. HamburgSteffen Sagave Radboud UniversityAlexander Samokhin HHU DusseldorfAnand Sawant LMU, MunchenJulia Schulz Univ. HamburgBjorn Schuster Univ. BochumNikita Semenov LMU MunchenMarkus Spitzweck Univ. OsnabruckSven Stahn Univ.f WuppertalVesna Stojanoska Univ. of IllinoisSean Tilson Univ. WuppertalKonrad Voelkel Univ. OsnabruckMaria Yakerson Univ. Duisburg-EssenXuan-Gottfried Yang independent researcherMarcus Zibrowius Univ. Dusseldorf
For further information on the meeting, please see the conference webpage
www.uni-due.de/˜bm0032/SPP1786/Web/Jahrestagung_2017.shtml
•Use of SPP fundingFor this meeting, the SPP supported per diem, hotel and travel expensesfor the speakers and in addition hotel and/or travel expenses for selectedparticipants.
Expense type Total in eSpeaker per diem 1.800Hotel & travel 7.677Total 9.477
Conference
Tropical curve counts, motivic integration, nonarchimedean geometry andrelations with motivic nearby cycles functor
Tubingen, March 27-31, 2017
SPP 1786 Homotopy Theory and Algebraic Geometry
1. Participants and Speaker
A star marks Postdoc resp. PhD student participants.
1.1. Speaker.
• Ilia Itenberg, Jussieu Paris
• Joe Rabinoff, Georgia Tech
• Julien Sebag, Rennes
• Diane Maclagan, Warwick
• Florian Ivorra, Rennes
• Lothar Gottsche, Trieste
• Franziska Schroeter, Hamburg∗
• Lorenzo Fantini, Jussieu∗
• Grigory Mikhalkin, Geneve
• Klaus Kunnemann, Regensburg
• Helge Ruddat, Mainz
• Andreas Gathmann, Kaiserslautern
• Peter Overholser, Mainz∗
• Lev Blechman, Tel Aviv∗
• Eugenii Shustin, Tel Aviv
• Kristin Shaw, Leipzig∗
1.2. Further Participants.
1.2.1. Postdocs whose attendance was funded by SPP 1786.
• Giuliano Gagliardi, Hannover∗
• Andreas Gross, Imperial London∗
• Philipp Jell, Regensburg∗
• Alejandro Soto, Frankfurt∗
1.2.2. Participants without funding.
• Anton Deitmar, Tubingen
• Boulos El-Hilany, Tubingen∗
• Christoph Goldner, Tubingen∗
• Marvin Hahn, Tubingen∗
• Ruben Jakob, Tubingen
• Hannah Markwig, Tubingen
• Thomas Markwig, Tubingen
• Johannes Rau, Tubingen
• Arthur Renaudineau, Tubingen∗
• Karin Schaller, Tubingen∗
• Veronika Wanner, Regensburg∗
2. Costs
2.1. Costs covered by SPP 1786.
5814 lodging costs for Itenberg, Mikhalkin, Shaw, Shustin, Ivorra, Rabinoff, Fantini, Gross, Soto,
Blechman, Jell, Sebag, Gathmann, Kunnenmann, Gottsche
261 travel costs Rabinoff
139,80 travel costs Fantini
163,51 travel costs Gross
43,50 travel costs Soto
462,50 travel costs Blechman
26,25 travel costs Jell
136,70 travel costs Gagliardi
311,14 travel costs Gottsche
124,20 travel costs Schroeter
228,48 travel costs Maclagan
107,27 Coffee breaks
7818,35
2.2. Further cost covered by other sources.
282 travel costs Itenberg
258 travel costs Mikhalkin
284 travel costs Shaw
640 travel costs Shustin
212 travel costs Sebag
212 travel costs Ivorra
62 travel costs Gathmann
69 travel costs Kunnemann
114 travel costs Ruddat
114 travel costs Overholser
250 costs for organization and coffee breaks (student assistance)
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3. Scientific Content
The focus of the conference was on new connections in the areas of tropical geometry, Arakelov theory,
and (non-archimedean) algebraic geometry, e.g. tropical quantum counts, motivic integration, and relations
with motivic nearby cycles functors.
Tropical curve counts emerged around 2003. Back then, it was surprising that both counts of complex
curves satisfying point conditions (Gromov-Witten invariants) and (signed) counts of real curves satisfying
point conditions (Welschinger invariants) can be expressed in terms of an efficient combinatorial count of
piece-wise linear graphs in a real vector space — tropical curves. Block and Gottsche defined a polynomial
multiplicity for counts of tropical curves yielding the Block-Gottsche polynomial Pd(y), such that specia-
lizing to y = 1 we obtain the Gromov-Witten invariant Nd (the number of degree d rational plane curves
through 3d − 1 points in general position), while specializing to y = −1 we obtain Wd (the Welschinger
invariant of degree d rational plane curves satisfying 3d− 1 real point conditions). Last year, an approach
by Nicaise-Payne-Schroeter attempts to shed light on the mysteries of the Block-Gottsche polynomial by
means of motivic integration.
The conference started with a talk of Itenberg presenting latest bounds on the number of real solutions
for polynomials, which can be viewed as a first step towards counts of real curves. Rabinoff continued with
a presentation of the skeleton of a variety defined over a complete field with a non-archimedean valuation in
its Berkovich space, and its connections to tropical varieties. Sebag started a series of two talks concerning
motivic nearby cycles, introducing arc schemes and motivic zeta functions. Maclagan gave an overview of
results concerning scheme structure for tropical varieties. Ivorra continued the series on motivic nearby
cycles presenting results on the mixed Hodge structure of nearby cycles, where the weight zero part can be
expressed in terms of the singular cohomology of the Berkovich space. Gottsche presented a generalization of
the polynomial count of tropical curves, where we obtain an interpolation between more general Welschinger
invariants (where in addition to real point conditions also pairs of complex conjugate points are allowed)
and descendant Gromov-Witten invariants, by means of tropical curve counts. Schroeter presented her
joined work with Nicaise and Payne relating Block-Gottsche multiplicities to motivic integration. Fantini
considered non-archimedean links of surface singulatities in terms of combinatorics. Mikhalkin discussed
the realizability of differential forms and divisors on tropical curves in the context of the non-archimedean
setting of tropicalization. Kunnemann presented his joint work with Gubler, and works of their students,
on cohomology theories for Berkovich spaces. Ruddat introduced tropical versions of descendant Gromov-
Witten invariants.
Gathmann considered tropical curve counts as intersection products on a moduli space of tropical
curves. Overholser gave an overview of recent applications of descendant Gromov-Witten invariants in the
tropical world. Blechman introduced a general polynomial tropical curve count, which has the potential to
generalize the Block-Gottsche interpolation. Shustin presented results concerning counts of plane curves
with a cusp and nodes under tropicalization. Shaw presented combinatorial analogues of Chern-Schwartz-
MacPherson classes for matroids in terms of tropical linear spaces, motivated by the case of hyperplane
arrangements.
The conference shed light on the various connections between nearby fibers, motivic integration, Ber-
kovich theory, non-archimedean geometry and tropical geometry. There was an active atmosphere with
plenty of discussions among the participants going beyond the contents of the talks.
The organizers would like to thank SPP 1786 for support for this event.
1. Report on conference
1.1. Summary. The conference on Invertible objects and duality in derived alge-braic geometry and homotopy theory was highly successful. This conference tookplace during the week of April 3rd-7th, 2017 at the University of Regensburg. Therewere 15 invited speakers, including the keynote speaker Mike Hopkins, who gavea four part lecture series. The conference had 133 registered participants comingfrom institutions around the world.
The success of the conference was highly dependent on the many sources of fi-nancial support it received. The cost of supporting a large number of speakers, 7 ofwhich came from the United States, was over 20000e alone. Of the people who reg-istered for the conference, 99 applied for some financial support beyond what theirlocal sources could provide. Nearly all of the PhD students and postdocs attend-ing received full support for accommodation and some received partial support fortravel costs. This support was primarily paid for from the SFB 1085 in Regensburg,which allocated 40000e for the conference, the additional 10000e support from theSPP 1786 made it possible to support many additional participants. Many of theseparticipants were from the United States and we were able to support 29 juniorparticipants with a separate grant from the NSF of $25000.
1.2. Video lecture series. We were able to coordinate with local resources tohave all of the invited lectures recorded and placed online. Videos are available atthe following links:
• https://mediathek.uni-regensburg.de/m/play/playlist/playlist_id/
153
• https://mediathek.uni-regensburg.de/m/play/playlist/playlist_id/
158
1.3. Informal Session. The conference included an informal session where 12junior participants (mostly PhD students) were invited to present short lectureson their research. All participants were provided with pizza, salad, and beverages.Feedback from the participants was very positive.
1.4. Excursion. To help foster social interaction and collaboration, the confer-ence included an afternoon excursion to the Monastery Weltenburg. The excursionincluded a pleasant hike through the Bavarian forest ending at the monastery.
1.5. Outreach. In addition to the standard channels for advertising such a confer-ence (posters, MathMeetings.net, and the ALGTOP mailing list), the conferencealso reached out to the Women in Topology network to help improve our visibilityto underrepresented groups. Four of our fifteen invited lecturers and many of theparticipants were female which can be seen from the list of participants below.
2. Speakers
(1) Mike Hopkins (Harvard). Keynote speaker with 4 lectures.(2) Benjamin Antieau (UIC).(3) Agnes Beaudry (University of Colorado).(4) Denis-Charles Cisinski (Regensburg).(5) David Gepner (Purdue).(6) John Greenlees (Sheffield).
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(7) Kathryn Hess (EPFL).(8) Mike Hill (UCLA).(9) Lennart Meier (Utrecht).
(10) Sarah Scherotzke (Bonn).(11) Thomas Schick (Gottingen).(12) Urs Schreiber (Czech Academy of Sciences).(13) Vesna Stojanoska (Illinois).(14) Gabriele Vezzosi (Florence).(15) Craig Westerland (Minnesota).
3. Registered participants
(1) Absmeier, Dominik (Bochum)(2) Antieau, Ben (UIC)(3) Arkhipov, Sergey (Aarhus)(4) Arndt, Peter (Dsseldorf)(5) El asery, Naima (Casablanca)(6) Baker, Andrew (Glasgow)(7) Balmer, Paul (UCLA)(8) Bandklayder, Lauren (Northwestern)(9) Barthel, Tobias (Copenhagen)
(10) Beaudry, Agnes (Boulder)(11) Berman, John (Virginia)(12) Berry, Eric (Montana State University)(13) Bhattacharya, Prasit (Notre Dame)(14) Bhme, Benjamin (Copenhagen)(15) Bonventre, Peter (Virginia)(16) Bunke, Ulrich (Regensburg)(17) Cameron, James (University of Washington)(18) Campbell, Jonathan (Vanderbilt)(19) Carlson, Kevin (UCLA)(20) Cepek, Anna (Montana State University)(21) Charalambous, Georgios (Cambridge)(22) Cisinski, Denis-Charles (Regensburg)(23) Clough, Adrian (UT Austin)(24) Columbus, Tobias (Karlsruher Institut fur Technology)(25) Conde Lago, Jesus (Universidade de Santiago de Compostela)(26) Dahlhausen, Christian (Regensburg)(27) Debray, Arun (UT Austin)(28) Dotto, Emanuele (Bonn)(29) Ertl, Veronika (Regensburg)(30) Feng, Yue (Tsinghua)(31) Fontes, Ernest E. (UT Austin)(32) Frankland, Martin (Osnabruck)(33) Friedrich, Roland (Saarland)(34) Gagna, Andrea (Aix-Marseille Universit)(35) Gepner, David (Purdue)(36) Gheorghe, Bogdan (Wayne State)(37) Goerss, Paul (Northwestern)
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(38) Greenlees, John (Sheffield)(39) Hahn, Jeremy (Harvard)(40) Hausmann, Markus (Copenhagen)(41) Hayashi, Takuma (Tokyo)(42) Heard, Drew (Hamburg)(43) Hebestreit, Fabian (Bonn)(44) Hedenlund, Alice (Oslo)(45) Heine, Hadrian (Osnabrck)(46) Heller, Jeremiah (University of Illinois)(47) Hellstrom-Finnsen, Magnus (NTNU Trondheim)(48) Henn, Hans-Werner (Strasbourg)(49) Herr, Leo (CU Boulder)(50) Hess, Kathryn (EPFL)(51) Hesse, Jan (Hamburg)(52) Hill, Mike (UCLA)(53) Hopkins, Mike (Harvard)(54) Huan, Zhen (UIUC)(55) Jin, Fangzhou (Regensburg)(56) Joachim, Michael (Munster)(57) Kedziorek, Magdalena (EPFL)(58) El Khamouri, Fatima Zahra (Hassan University II - Casablanca)(59) Khan, Adeel (Regensburg)(60) Koerschgen, Alex (Bonn)(61) Kodjabachev, Dimitar (Sheffield)(62) Kufner, Hanno (Regensburg)(63) Francois, Kevin (Toulouse)(64) Van Koughnett, Paul (Northwestern)(65) Kumar, Pankag (Skolkovo Institute of Science and Technology)(66) Land, Markus (Regensburg)(67) Laures, Gerd (Bochum)(68) Li, Guchuan (Northwestern)(69) Luckhardt, Daniel (Gottingen)(70) Luders, Morten (Regensburg)(71) Mazel-Gee, Aaron (Ohio State)(72) Meier, Lennart (Bonn)(73) Moulinos, Tasos (UIC)(74) Nassau, Christian (nullhomotopie)(75) Naumann, Niko (Regensburg)(76) Nelson, Peter (Haifa)(77) Nguyen, Manh Toan (Osnabruck)(78) Nicotra, Stefano (Liverpool)(79) Nikolaus, Thomas (Bonn)(80) Noel, Justin (Regensburg)(81) Otmani, Hind (Casablanca)(82) Ozornova, Viktoriya (Bonn)(83) Patchkoria, Irakli (Bonn)(84) Peterson, Eric (Harvard)(85) Pham, Viet-Cuong (University of Strasbourg)
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(86) Pohl, Gregor (Heidelberg)(87) Pol, Luca (Sheffield)(88) Poliakova, Daria (HSE Moscow)(89) Prasma, Matan (Regensburg)(90) Quick, Gereon (NTNU Trondheim)(91) Quigley, J.D. (Notre Dame)(92) Raptis, George (Regensburg)(93) Ray, Catherine (Chicago)(94) Ricka, Nicolas (Wayne State)(95) Robalo, Marco (Institut Mathematiques Jussieu)(96) Rok, Gregoric (Ljubljana)(97) Sanders, Beren (Copenhagen)(98) Sagave, Steffen (Nijmegen)(99) Sarwar, Husney Parvez (Tata Institute of Fundamental Research)
(100) Schaeppi, Daniel (Regensburg)(101) Scherotzke, Sarah (Bonn)(102) Schick, Thomas (Gottingen)(103) Schreiber, Urs (CAS)(104) Schulenberg, Nils (Bochum)(105) Schulz, Julia (Hamburg)(106) Seeliger, Nora (Haifa)(107) Shaul, Liran (Bielefeld)(108) Shi, Xiaolin Danny (Harvard)(109) Sia, Charmaine (Indiana)(110) Sigloch, Helene (Regensburg)(111) Simkova, Maria (Masaryk University Brno)(112) Sorokin, Oleksiy (Ivan Franko National University)(113) Stapleton, Nat (Regensburg)(114) Stelzer, Manfred (Osnabruck)(115) Stojanoska, Vesna (UIUC)(116) Strunk, Florian (Regensburg)(117) Sulyma, Yuri (UT Austin)(118) Syed, Tariq (LMU Munich)(119) Verchinine, Vladimir (Montpellier)(120) Vezzosi, Gabriele (Florence)(121) Volkel, Konrad (Osnabruck)(122) Wen, Joshua (UIUC)(123) Werndli, Kay (Utrecht)(124) Westerland, Craig (Minnesota)(125) Williamson, Jordan (Sheffield)(126) Wilson, Dylan (Northwestern)(127) Wimmer, Christian (Bonn)(128) van Woerden, Koen (Regensburg)(129) Wong, Richard (UT Austin)(130) Yang, Xuan-Gottfried(131) Yoshida, Jun (Tokyo)(132) Yuan, Allen (MIT)(133) Zibrowius, Marcus (Dusseldorf)
REPORT ON: THE TRANSATLANTIC TRANSCHROMATIC
HOMOTOPY THEORY CONFERENCE
ORGANIZED BY: TOBIAS BARTHEL AND NATHANIEL STAPLETON
Contents
1. Short description of the format of the workshop 12. Short description of the topic of the workshop 13. Outcome of the workshop 14. List of speakers 25. List of registered participants and contributed talks 26. Budget summary 3
1. Short description of the format of the workshop
The purpose of the event was to bring together researchers at all levels as well asstudents interested in the interplay between chromatic heights, and as such was thefirst international conference on transchromatic homotopy theory. The audiencecovered a wide variety of interests: people working on field theories, computationsin stable homotopy theory, the algebraic geometry of p-divisible groups, and thelocal Langlands program.
The workshop consisted of 11 talks by leading experts in the subject, 6 half hourtalks by graduate students and early-career postdocs, as well as an open problemsession in which participants contributed open questions and conjectures for futureresearch. It was cofunded by the SFB 1085 in Regensburg, and it took place at theUniversity of Regensburg in June 2017.
2. Short description of the topic of the workshop
Transchromatic homotopy theory studies the relationship between the differentchromatic layers in stable homotopy theory. This leads to an important and novelinterplay between homotopy theory and algebraic geometry. What is more, this be-havior is analogous to phenomena appearing in the Stolz–Teichner program relatingtopology and supersymmetric field theories in mathematical physics.
Consequently, this workshop focused on transchromatic phenomena in stable andunstable homotopy theory, higher category theory, topological field theories, andarithmetic geometry. Topics that were discussed during the workshop include:
• Redshift in algebraic K-theory and topological cyclic homology.• Dimensional reduction in field theories.• Transchromatic character theory.• The analogy between category number, dimension in field theories, and
chromatic height.1
REPORT ON: THE TRANSATLANTIC TRANSCHROMATICHOMOTOPY THEORY CONFERENCE2
• Moduli of p-divisible groups and incarnations of the Langlands correspon-dence in stable homotopy theory.
• The chromatic splitting conjecture and analogues in algebraic categories.
3. Outcome of the workshop
The workshop attracted both leading experts and young researchers in the sub-ject from around the world. The talks portrayed the state of the art in tran-schromatic homotopy theory and explored several directions for future research,connecting the subject to both arithmetic geometry and mathematical physics.
The main and contributed talks were recorded and will be made available by theUniversity of Regensburg, subject to agreement by the speakers. More informationcan be found at the workshop’s homepage http://www-app.uni-regensburg.de/
Fakultaeten/MAT/sfb-higher-invariants/index.php/SFB_transchromatic_2017.
4. List of speakers
This is the list of speakers, together with the titles of their talks.
(1) Andrew Baker (Finitely generated commutative S-algebras)(2) Agnes Beaudry (Perspectives on the Chromatic Splitting Conjecture)(3) Mark Behrens (The telescope conjecture from the motivic point of view)(4) Paul Goerss (Qualitative Transchromatic Phenomena)(5) Gerd Laures (On the chromatic atoms of Thom spectra)(6) Matthew Morrow (Topological cyclic homology and p-adic Hodge theory)(7) Charles Rezk (Complex analytic elliptic cohomology and double loop groups)(8) Birgit Richter (Towards topological Hochschild homology of Johnson–Wilson
spectra)(9) Andrew Salch (Special values and the height-shifting spectral sequence)
(10) Tomer Schlank (Ultraproducts and Chromatic Homotopy Theory)(11) Chris Schommer-Pries (Parallels between transchromatic character theory
and QFT dimensional reduction)
5. List of registered participants and contributed talks
This is the list of all participants of the workshop. The junior speakers whocontributed a 30 minute talk at the workshop are stared (*).
(1) Dominik Absmeier(2) Gabe Angelini-Knoll*(3) Lauren Bandklayder*(4) Jonathan Beardsley*(5) Dan Berwick-Evans(6) Irina Bobkova(7) Denis-Charles Cisinski(8) Martin Frankland(9) Drew Heard
(10) Fangzhou Jin(11) Moritz Kerz(12) Adeel Khan(13) Andrei Konovalov(14) Johan Konter
REPORT ON: THE TRANSATLANTIC TRANSCHROMATICHOMOTOPY THEORY CONFERENCE3
(15) Achim Krause(16) Niko Naumann(17) Peter Nelsen*(18) Kim Nguyen(19) Alon Nissan-Cohen(20) Justin Noel(21) Dmitri Pavlov(22) Eric Peterson(23) Matan Prasma(24) Georgios Raptis(25) Charmaine Sia(26) Helene Siegloch(27) Georg Tamme(28) Sean Tilson(29) Gabriel Valenzuela(30) Paul VanKoughnett*(31) Koen van Woerden(32) David White(33) Lior Yanovski*(34) Ugur Yigit(35) Yigeng Zhao
6. Budget summary
Here is the summary of the funds requested from the SPP and the correspondingexpenses. The conference was cofunded by the SFB 1085 and expenses covered bythem are not listed here.
Amount in Euro
Total funds from SPP 1786 10000ExpensesTravel (participants) -921.37Travel (speakers) -449.55Lodging (participants) -738Lodging (speakers) -4189.5Total expenses -6298.42
Balance 3701.58
Report on: The European Talbot Workshop 2017Dualities in Algebra, Geometry, and Topology
Mentored by John Greenlees and Mike Hill
Contents
1. Short description of the format of the workshop 12. Short description of the topic of the workshop 13. Outcome of the workshop 14. List of participants and speakers 25. Budget summary 2
1. Short description of the format of the workshop
The workshop brought together a group of 33 graduate students and post-docsto stay and work together for one week on a specific topic, under the guidance oftwo senior mentors. Most of the talks were given by the participants, and there wasplenty of free time for further discussions and collaborations. The character of theworkshop was expository in nature, starting with the basic ideas and leading to asurvey of the most recent developments in the field. Since all participants stayedtogether at a cottage in Germany, jointly responsible for cooking and cleaning, itwas possible to create an inclusive and inspiring atmosphere.
It was mentored by two of the world-leading experts in the field, John Green-lees and Mike Hill, and took place in Germany in June 2017. More informationcan be found at the workshop’s homepage http://hessbellwald-lab.epfl.ch/
talbot17.
2. Short description of the topic of the workshop
The focus of the workshop was on various forms of dualities in commutativealgebra, (derived) algebraic geometry, and equivariant homotopy theory. The threemain themes of the workshop were:
(1) Gorenstein duality in algebra,(2) Serre duality in geometry, and(3) group actions,
brought together in a homotopy invariant context and illustrated by examples fromalgebra, chromatic homotopy theory, and modular forms.
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3. Outcome of the workshop
The workshop was highly successful, and we received plenty of positive feedbackboth from the participants and the mentors. Starting from the basic notions in com-mutative algebra and homotopy theory, we reached the frontiers of current researchon dualities in derived algebraic geometry. Beyond the immense scientific and socialvalue of the event, fostering collaborations between the young participants, one ofthe participants (Liran Shaul) has already produced a preprint directly credited tothe workshop. Furthermore, we are currently collecting notes for the talks whichwe hope to make available to a wider audience soon.
As indicated by the list of participants below, the workshop attracted a widevariety of graduate students and young postdocs from many different institutionsboth within Europe and beyond. Their research interests covered all aspects of theworkshop, reflecting the mathematical breadth of the topic. Furthermore, 9 out ofthe 29 invited participants were female.
4. List of participants and speakers
This is the list of all participants of the workshop, including position and affili-ation. The names of people who contributed a talk are stared (*).
(1) Dominik Absmeier (Ruhr-Universitat-Bochum, 2nd year PhD student)(2) Katharine Adamyk* (University of Colorado, 3rd year PhD student)(3) Bertram Arnold (Max Planck Institute Bonn, 1st year PhD student)(4) Tom Bachmann* (University of Duisberg–Essen, PostDoc)(5) Tobias Barthel (University of Copenhagen, PostDoc)(6) Ben Briggs* (University of Toronto, 4th year PhD student)(7) Dominic Culver* (University of Notre Dame, 5th year PhD student)(8) Jack Davies* (Bonn Universitat, Master student)(9) John Greenlees* (University of Sheffield, Professor)
(10) Alice Hedenlund* (University of Oslo, 1st year PhD student)(11) Mike Hill* (UCLA, Professor)(12) Joshua Hunt (University of Copenhagen, Master student)(13) Jocelyne Ishak* (University of Kent, 2nd year PhD student)(14) Magdalena Kedziorek (EPFL Lausanne, PostDoc)(15) Pax Kivimae (Northwestern University, 1st year PhD student)(16) Inbar Klang (Stanford University, 4th year PhD student)(17) Dimitar Kodjabachev* (University of Sheffield, 3rd year PhD student)(18) Juultje Kok (KU Leuven, 1st year PhD student)(19) Johan Konter* (Northwestern University, 5th year PhD student)(20) Achim Krause* (Max Planck Institute Bonn, 4th year PhD student)(21) Janina Letz* (University of Utah, 2nd year PhD student)(22) Anja Meyer (Georg-August Universitat Gottingen, Master student)(23) Alon Nissan-Cohen (Hebrew University Jerusalem, 2nd year)(24) Viktoriya Ozornova (Bonn Universitat, PostDoc)(25) Eric Peterson* (Harvard University, PostDoc)(26) Luca Pol* (University of Sheffield, 1st year PhD student)(27) J.D. Quigley* (University of Notre Dame, 3rd year PhD student)(28) Julia Semikina (Bonn Universitat, 3rd year PhD student)(29) Jay Shah* (MIT, 5th year PhD student)
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(30) Liran Shaul* (Bielefeld University, PostDoc)(31) Sean Tilson (Bergische Universitat Wuppertal, PostDoc)(32) Jordan Williamson (University of Sheffield, 1st year PhD student)(33) Richard Wong (UT Austin, 2nd year PhD student)(34) Lior Yanovski (Hebrew University Jerusalem, 3rd year PhD student)(35) Mingcong Zeng (University of Rochester, 4th year PhD student)
5. Budget summary
Here is the summary of the requested funds for the workshop and the expenses.A more detailed description has been sent to the SPP 1786 and is also availableupon request from the organizers.
Amount in Euro
Total funds 15000ExpensesTransportation (speakers) -403.13Transportation (participants) -1195.25Local expenses (food) -1887.49Lodging (participants and speakers) -8410Social event -60Total expenses -11955.87
Balance 3044.13
Workshop: Infinity Operads and Applications
Osanbruck, 12-14 July 2017
Infinity-operads have attracted a great deal of attention from the homotopytheory community and their potential for applications is now being explored indifferent fields. This workshop gave its participants the chance to learn aboutthe existing models for infinity operads, the relation between them and some oftheir most recent applications. The workshop consisted of a 9-hour long mini-course entitled “Lectures on dendroidal topology” as well as several researchtalks.
http://userpage.fu-berlin.de/jcirici/infinityoperads/index.html
Organizers
• Hongyi Chu (Universite Lille 1)
• Joana Cirici (WWU Munster)
• Oriol Raventos
• Markus Spitzweck (Universitat Osnabruck).
Mini-Course
• Gijs Heuts (University of Copenhagen)
• Javier J. Gutierrez (University of Barcelona)
• Ieke Moerdijk (Universiteit Utrecht)
Research Talks
• Pedro Boavida (University of Lisbon)
• Philip Hackney (Macquarie University of Sydney)
• Rune Haugseng (University of Copenhagen)
• Brice Le Grignou (Universiteit Utrecht)
• Marcy Robertson (University of Melbourne)
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List of Participants
• Matija Basic (University of Zagreb)
• Pedro Boavida (University of Lisbon)
• Benjamin Bohme (University of Copenhagen)
• Simon Brun (ETH Zurich)
• Ricardo Campos (ETH Zurich)
• Paolo Capriotti (University of Nottingham)
• Jin Cao (Tsinghua University, YMSC)
• Hongyi Chu (Universitat Osnabruck)
• Joana Cirici (University of Munster)
• Peter James Dawson (Utrecht University)
• Lennart Duppenschmitt(ETH Zurich)
• Julien Ducoulombier (ETH Zurich)
• Daniela Egas Santander (Freie Universitat Berlin)
• Martin Frankland (Universitat Osnabruck)
• Thomas Gunnarsson (Lulea university of technology)
• Javier J. Gutierrez (University of Barcelona)
• Philip Hackney (Macquarie University of Sydney)
• Redi Haderi (Bilkent University)
• Heine Hadrian (Universitat Osnabruck)
• Rune Haugseng (University of Copenhagen)
• Magnus Hellstrøm-Finnsen (NTNU, Trondheim)
• Gijs Heuts (University of Copenhagen)
• Geoffroy Horel (Univertite Paris 13)
• Sacha Ikonicoff (Paris 7 Diderot)
• Rigel Juarez (University of Artois)
• Jens Jakob Kjaer (University of Notre Dame)
• Arun Kumar (Universitat Osnabruck)
• Hoang Kim Nguyen (University of Regensburg)
• Satyendra Kumar Mishra (IIT Kanpur)
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• Brice Le Grignou (Universiteit Utrecht)
• Filipp Levikov (Freie Universitat Berlin)
• Ieke Moerdijk (Universiteit Utrecht)
• Lukas Muller (Heriot-Watt University Edinburgh)
• Manh Toan Nguyen (Universitat Osnabruck)
• George Raptis (University of Regensburg)
• Oriol Raventos
• Sophia Raynor (Aberdeen University)
• Marcy Robertson (University of Melbourne)
• Oliver Rondigs (Universitat Osnabruck)
• Sarah Yeakel (University of Maryland)
• Markus Spitzweck (Universitat Osnabruck)
• Manfred Stelzer (Universitat Osnabruck)
• Sabrina Syed (Universitat Osnabruck)
• Paula Verdugo (Universitat Osnabruck)
• Tim Weelinck (University of Edinburgh)
• Jonathan Weinberger (TU Darmstadt)
• David White (Denison University)
• Lukas Woike (Universitat Hamburg)
Budget
• Travel and accommodation for 8 speakers
• Conference dinner for 8 speakers
• Accommodation for 14 funded participants
• Travel expenses for 5 participants
• Coffee breaks and material
Total Approx: 10.000Euro
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REPORT ON THE CONFERENCEMOTIVES FOR PERIODS
The summer school Motives for Periods was held from 28 August to 1 September,2017 at the Freie Universität of Berlin. Around forty PhD students and young researchersattended the event. The organisers would like to emphasize the friendly atmospherethat reigned among the participants, as well as the many scientific exchanges duringthe week. The conference would have not been possible without the generous financialsupport of the following institutions:
• SPP 1786 “Homothopy Theory”,• ERC Starting Grant “AlgTateGro”,• Fondation Compositio Mathematica,• Berlin Mathematical School.
CONTENTS
Organizing and scientific committees 2
Scientific program 3
Schedule 7
List of Participants 8
Financial support 10
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2
ORGANIZING AND SCIENTIFIC COMMITTEES
Scientific committee
• Name: José Ignacio Burgos GilPosition: ProfessorAffiliation: ICMAT Madride-mail: [email protected]
• Name: Hélène EsnaultPosition: ProfessorAffiliation: Freie Univesität Berline-mail: [email protected]
Scientific committee
• Name: Giuseppe AnconaPosition: Maître de conférencesAffiliation: Université de Strasbourge-mail: [email protected]
• Name: Javier FresánPosition: PostdocAffiliation: ETH Züriche-mail: [email protected]
• Name: Simon Pepin-LehalleurPosition: PostdocAffiliation: Freie Universitäte-mail: [email protected]
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SCIENTIFIC PROGRAM
The aim of the summer school “Motives for periods” was to introduce students andyoung researchers to different categories of motives and to illustrate them towards theirapplications to concrete questions on periods. The application of motivic ideas to pe-riods has a long story: for example, Deligne showed in the 80s that the transcendencedegree of periods of an abelian variety A is bounded by the dimension of the Mumford-Tate group of A. However, it was only very recently that a significant expansion was pos-sible thanks to the use of more modern techniques. Two striking examples are the proofof Hoffman’s conjecture on multiple zeta values by F. Brown and the relative analogueof the Kontsevich-Zagier conjecture by J. Ayoub. We had three minicourses presentingthese beautiful mathematics (by some of their creators).
J. Ayoub. – Triangulated categories of motives and the Kontsevich-Zagier conjecture
I will recall the construction of the triangulated categories of motives and dis-cuss various related topics (the Betti and de Rham realisations, the rigid analyticvariant, nearby motives, etc.). Then, I will recall the construction of the motivicGalois group and the torsor of motivic periods, and formulate the Kontsevich-Zagier conjecture on periods in this setting. Finally, I will formulate a geometricversion of the Kontsevich-Zagier conjecture and explain its proof.
C. Dupont. – Mixed Tate motives and multiple zeta values
Multiple zeta values (MZVs) generalize the values of the Riemann zeta functionat integer points and form a fascinating algebra of real numbers. They appearin a wide variety of contexts, ranging from the theory of associators to the com-putation of amplitudes in particle physics. Since MZVs are periods, it is naturalto introduce their motivic versions, which are acted upon by a motivic Galoisgroup. Surprisingly enough, the Galois theory of motivic MZVs can be madeentirely explicit and used to prove powerful theorems on real MZVs. The goalof this minicourse will be to explain the proofs of these theorems, with a spe-cial emphasis on Brown’s recent proof of a conjecture of Hoffman. The relevantmotivic framework is that of mixed Tate motives and their tannakian formalism,which we will review.
P. Jossen . – Nori motives and exponential periods
In my lectures, I will present joint work with Javier Fresán. Our departing pointis the observation that several interesting transcendence theorems and conjec-tures are about numbers which presumably are not periods in the usual sense,so Grothendieck’s period conjecture says nothing about them. One such caseis the Lindemann-Weierstrass theorem which implies for example that e and
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ep
2 are algebraically independent, another one is the Rohrlich-Lang conjecturewhich claims that for any integer n ≥ 3, the transcendence degree of the field
Q(Γ( 1n ),Γ( 2
n ),Γ( 3n ), . . . ,Γ( n−1
n )) with Γ(s) :=∫ ∞
0xs−1e−x d x
is equal to 12ϕ(n)+ 1. Another rich source of transcendence statements is the
Siegel-Shidlovskii theorem, which shows for example that the number
∞∑n=1
(−1)n+1
n ·n!=
Ï0≤x,y≤1
e−x y d xd y
is transcendental. In their celebrated paper on periods, Kontsevich and Zagiermention that it should be possible to enlarge Nori’s tannakian category of mixedmotives to a tannakian category of exponential motives, together with realisa-tion functors and comparison isomorphisms between them. Whereas classicalmotives are associated to varieties, exponential motives are associated to pairs(X , f ), where X is an algebraic variety, and f is a regular function on X . Periodsfor exponential motives, which we call exponential periods, typically look like∫
γωe− f
where γ is a topological cycle on X (C) and ω an algebraic differential form. Inparticular, all the examples above concern exponential periods, and can be re-cast in terms of the period conjecture extended to exponential motives.
An optimistic outline for my lectures:(1) Construct some elementary cohomology theories for pairs (X , f ), and then
the category of exponential motives as a universal cohomology theory fol-lowing Nori’s method.
(2) Formulate the exponential period conjecture and give some examples andconsequences. Compare to the classical period conjecture.
(3) Construct some more involved cohomology theories, in particular the Hodgerealisation for exponential motives.
(4) Show on concrete examples how the Hodge realisation helps to computemotivic fundamental groups.
The school also gave the opportunity to some young mathematicians working in thearea to present their work, in the form of six 60 minutes talks:
M. Gallauer – Motivic Galois groups in characteristic 0
A central ingredient in Kim’s work on integral points of hyperbolic curves is the“unipotent Kummer map” which goes from integral points to certain torsorsfor the prounipotent completion of the fundamental group, and which, roughlyspeaking, sends an integral point to the torsor of homotopy classes of paths
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connecting it to a fixed base-point. In joint work with Tomer Schlank, we intro-duce a spaceΩ of “rational motivic loops”, and we construct a double factoriza-tion of the unipotent Kummer map which may be summarized schematicallyas
points → rational motivic points →Ω-torsors →π1-torsors.
Our “connectedness theorem” says that any two motivic points are connectedby a non-empty torsor. Our “concentration theorem” says that for an affinecurve,Ω is actually equal to π1. As a corollary, we obtain a factorization of Kim’sconjecture into a union of smaller conjectures with a homotopical flavor. Withsome luck, I’ll also be ready to discuss the problem of delooping in this setting.
M. Gallauer – Motivic Galois groups in characteristic 0
I will survey different approaches by various mathematicians to constructingthe Galois group for mixed motives over a field of characteristic 0. I will alsotry to elucidate the relation among these candidates, and explain why everyoneinterested in periods should care.
T. Jardim da Fonseca – Higher Ramanujan equations and periods of abelian varieties
The Ramanujan equations are certain algebraic differential equations satisfiedby the classical Eisenstein series E2,E4,E6. These equations play a pivotal rolein the proof of Nesterenko’s celebrated theorem on the algebraic independenceof values of Eisenstein series, which gives in particular a lower bound on thetranscendence degree of fields of periods of elliptic curves. Motivated by theproblem of extending the methods of Nesterenko to other settings, we shall ex-plain how to generalize Ramanujan’s equations to higher dimensions via a geo-metric approach, and how the values of a particular solution of these equationsrelate with periods of abelian varieties.
N. Matthes – Twisted elliptic multiple zeta values
We introduce an analog of multiple zeta values, which is naturally associatedto an elliptic curve together with a distinguished set of torsion points, the so-called “twisted elliptic multiple zeta values”. They generalize elliptic multiplezeta values, which were previously introduced by Brown–Levin and Enriquez,and are closely related to both cyclotomic multiple zeta values and iterated in-tegrals of modular forms for congruence subgroups. In a similar way as mixedTate motives over Z help to explain structural properties of multiple zeta val-ues, it is hoped that the algebraic structure of twisted elliptic multiple zeta val-ues can likewise be elucidated by a suitable category of mixed (elliptic) motives.
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This is joint work (partly in progress) with J. Broedel, M. Gonzalez, G. Richter,O. Schlotterer and F. Zerbini.
E. Panzer –The Galois coaction on φ4 periods
We discuss the structure of φ4 periods, focussing on the possibility that prim-itive φ4 periods span a comodule for the motivic coaction. This is joint workwith Oliver Schnetz and rests on a recently updated database of hundreds ofexact results for primitive graphs with up to eleven loops.
S. Ünver – Iterated sum series and p-adic multiple zeta values
p-adic multi-zeta values are the p-adic periods of the unipotent fundamentalgroup of the thrice punctured line. They turn out to give all the p-adic periodsof mixed Tate motives over Z. In this talk, I will give an explicit series represen-tation of these values in all depths. The new tool is a certain regularization trickfor p-adic series.
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SCHEDULE
Here is the schedule of the conference (3 courses of 5h30 and 6 talks of 1h):
Monday
9:30 – 11:00 Ayoub 111:30 –13:00 Dupont 114:30 – 16:00 Jossen 116:30 – 17:30 Ünver
Tuesday
9:30 – 11:00 Jossen 211:30 –13:00 Dupont 214:30 – 16:00 Ayoub 216:30 – 17:30 Jardim da Fonseca
Wednesday
9:00 – 10:00 Dupont 310:30 –11:30 Ayoub 312:00 – 13:00 Jossen 3
Thursday
9:30 – 11:00 Ayoub 411:30 –13:00 Dupont 414:30 – 15:30 Panzer16:00 – 17:00 Matthes
Friday
9:00 – 10:30 Jossen 411:00 –12:00 Dan-Cohen12:00 – 13:00 Gallauer Alves da Souza
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LIST OF PARTICIPANTS
1. Grétar AMAZEEN (FU Berlin)
2. Giuseppe ANCONA (Strasbourg)
3. Oliver Eivind ANDERSON (Liverpool)
4. Peter ARNDT (Düsseldorf)
5. Emelie ARVIDSSON (FU Berlin)
6. Joseph AYOUB (University of Zürich)
7. Olivier BENOIST (Strasbourg)
8. Alexey BESHENOV (Bordeaux and Leiden)
9. Yang CAO (Paris 11)
10. Pedro Ángel CASTILLEJO (FU Berlin)
11. Mattia CAVICCHI (Paris 13)
12. François CHARLES (Paris 11)
13. Steven CHARLTON (Tübingen)
14. Jiaming CHEN (Paris)
15. Johan COMMELIN (Nijmegen)
16. David CORWIN (MIT)
17. Ishai DAN-COHEN (Ben Gurion)
18. Clément DUPONT (Montpellier)
19. Javier FRESÁN (ETH Zürich)
20. Martin GALLAUER ALVES DA SOUZA (UCLA)
21. Martin GONZÁLEZ (Montpellier)
22. Tiago JARDIM DA FONSECA (Paris 11)
23. David JAROSSAY (Strasbourg)
24. Peter JOSSEN (ETH Zürich)
25. Daniel JUTEAU (IMJ-PRG)
26. Robert KUCHARCZYK (ETH Zürich)
27. Jonas Irgens KYLLING (Oslo)
28. Marcin LARA (FU Berlin)
29. Florence LECOMTE (Strasbourg)
30. Ma LUO (Duke University)
31. Nils MATTHES (Bonn)
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32. Alberto NAVARRO (University of Zurich)
33. Thi Quynh Trang NGUYEN (Edinburgh)
34. Stefano NICOTRA (Liverpool)
35. Owen PATASHNICK (Bristol)
36. Erik PANZER (Oxford)
37. Simon PEPIN LEHALLEUR (FU Berlin)
38. Iulia-Catalina PLESCA (Iasi)
39. Jishnu RAY (Orsay)
40. Fei REN (FU Berlin)
41. Alexander SAAD (Oxford)
42. Biswajyoti SAHA (TATA Institute)
43. Ekata SAHA (TATA Institute)
44. Xiaoyu SU (FU Berlin)
45. Jean-Baptiste TEYSSIER (KU Leuven)
46. Alex TORZEWSKI (Warwick)
47. Sinan ÜNVER (Koç University)
48. José VILLANUEVA GUTIÉRREZ (Bordeaux)
49. Linda XIAO (ETH Zürich)
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FINANCIAL SUPPORT
We received financial support from the following institutions:
• SPP 1786 “Homothopy Theory” (10000 euros),• ERC Starting Grant “AlgTateGro” (5000 euros),• Fondation Compositio Mathematica (4000 euros),• Berlin Mathematical School (2000 euros).
We used this amount roughly in the following way:
Accommodation5 nights for all participants 14000Travel expensesTrains or airplanes for speakers and some participants 4000Local expensesLunches for speakers and coffee breaks 2000Social dinnerOne dinner at a Biergarten for all participants 1000Total 21000
The precise use for each institution was as follows:
SPP 1786 “Homothopy Theory”Used for hotels 10000ERC Starting Grant “AlgTateGro”Travel and Local expenses 5000Fondation Compositio MathematicaHotel and Social dinner 4000Berlin Mathematical SchoolHotel and Local expenses 2000Total 21000
Final Report. VBAC (Vector bundles on algebraic curves) 2017The VBAC series is long-running conference series in algebraic geometry.Professor Emeritus Peter Newstead is Chair of the Coordinating Team ofthe international research group VBAC; the first VBAC meeting was heldin 1994 and the meeting has been held yearly since 2006. The 2017 meetingwas held at the Universitat Duisburg-Essen, September 4-8, 2017. The pro-gram consisted of two mini-course, one in Bridgeland stability, held by Em-manuel Macri, the other in noncommutative motives, by Goncalo Tabuada.In addition, we held a series of 14 lectures representing a mixture of alge-braic geometry and motivic homotopy theory. The conference was fundedjointly by the SPP and the SFB Transregio 45.
• OrganizersName AffiliationGeorg Hein Univ. Duisburg-EssenMarc Levine Univ. Duisburg-Essen
• SpeakersName Affiliation Lecture TitleMini-courses:Emmanuel Macri Northeastern University Bridgeland stabilityGoncalo Tabuada MIT Noncommutative motivesLectures:Aravind Asok USC Counting vector bundlesMarcello Bernardara Univ Paul Sabatier Families of Segre fourfolds
with a view to del Pezzofibrations of degree 6
Jean Fasel Inst. Fourier MW-motivic cohomologyDaniel Halpern-Leistner Columbia University Beyond geometric invariant
theoryJesse Kass Univ. of South Carolina How to count lines on a
cubic surface arithmeticallyMarkus Reineke Univ. Bochum Intersection cohomology of
moduli spaces ofvector bundles on curves
Wolfgang Soergel Univ. Freiburg Equivariant Motives inRepresentation Theory
David Stapleton SUNY Stony Brook Geometry and stability oftautological bundles onHilbert schemes of points
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Name Affiliation Lecture TitleSofia Tirabassi Univ. Bergen Derived categories of
canonical covers inpositive characteristic
Pieter Belmans Univ. Antwerp Hochschild-Kostant- Rosen-berg decomposition versusnoncommutative surfaces
Marcos Jardim Univ. Campinas Moduli spaces of rank 2sheaves on projective spaceand Bridgeland stability
Chiara Damiolini Univ. Duisburg-Essen Twisted conformal blocksAlejandra Rincn Hidalgo FU Berlin Bridgeland stability
conditions on the categoryof holomorphic triplesover a curve
Charles Aparecido de Almeida Univ. of Campinas New moduli componentsof rank 2 bundleson projective space
• Participants and Program
There were 57 registered participants for the meeting.For further information on the meeting, including the detailed lecture
program and a list of registered participants, please see the conference web-page
www.uni-due.de/˜hm0019/vbac2017/
•Use of SPP fundingAs mentioned above, the meeting was funded jointly by the SPP and theSFB Transregio 45; the expenses were divided more or less equally. TheSPP supported hotel and travel expenses for the speakers as well as theconference dinner for the speakers, coffee and a conference cultural activity.
Expense type Total in eHotel and Travel 4.514Other 1.184Total 5.698
Report on the workshopÉtale and motivic homotopy theory
18.–22.10.2017 Heidelberg
The workshop took place in the new Heidelberg math building, the Mathe-matikon. Organizers were
Prof. Dr. Alexander Schmidt (Heidelberg University)Prof. Dr. Jakob Stix (University of Frankfurt)
There were 34 participants from 10 countries. This was a little less than origi-nally planed, the probable reasons were concurrent conferences in Bukarest andTokyo. As a result, there was a larger proportion of young researchers amongthe participants, which was a good thing in the end.
The schedule consisted of 18 one-hour-talks, a conference hike and a con-ference dinner. The talks covered topics around motivic and étale homotopytheory. On Tuesday, J. Ayoub gave a double talk on the conservativity conjec-ture, other talks were centered around algebraic K-theory and the arithmeticof fundamental groups. 3 of the 17 speaker were women.
The organizers consider the workshop as very successful. In particular, therewas a good mixture of senior and junior researchers and there were lively dis-cussions.
The expected budget of the conference will be around 22.300 Euro. Anamount of 10.000 Euro (a part of the hotel costs) was covered by the SPP1786, the remaining costs were, resp. will be covered by the DFG ResearchGroup 1920 “Symmetry, geometry, and arithmetic”.
List of participants:
Name Affiliation1 Piotr Achinger IHES Paris2 Joseph Ayoub Zurich University3 Tom Bachmann Universität München4 Giulia Battiston Universität Heidelberg5 Alexander Betts University of Oxford6 David Carchedi GMU Fairfax7 Benjamin Collas Universität Bayreuth8 Thomas Geisser Rikkyo University, Tokyo9 Gabriela Guzman Universität Duisburg-Essen10 Katharina Hübner Universität Heidelberg11 Moritz Kerz Universität Regensburg12 Robert Kucharczyk ETH Zürich13 Jonas Irgens Kylling University of Oslo14 Andrei Lavrenov Universität München15 Daniel Litt Columbia NYC16 Martin Lüdtke Universität Frankfurt17 Lorenzo Mantovani Universität Duisburg-Essen18 Fabien Morel Universität München19 Baptiste Morin CNRS Bordeaux
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20 Paul Arne Østvaer University of Oslo21 Gregor Pohl Universität Heidelberg22 Oliver Röndigs Universität Osnabrück23 Tomer Schlank University of Jerusalem24 Alexander Schmidt Universität Heidelberg25 Johannes Schmidt Universität Heidelberg26 Pavel Sechin Universität Heidelberg27 Nikita Semenov Universität München28 Markus Spitzweck Universität Osnabrück29 Jakob Stix Universität Frankfurt30 Florian Strunk Universität Regensburg31 Tamás Szamuely Rényi Institute Budapest32 Matthias Wendt Universität Duisburg-Essen33 Kirsten Wickelgren Georgia Tech34 Maria Yakerson Universität Duisburg-Essen
List of talks:
Piotr Achinger Log geometry, monodromy, and Betti realization of varietiesdefined by formal power series
Joseph Ayoub On the conservativity conjecture I & IIGiulia Battiston Gauß Manin stratifications and a Künneth formulaDavid Carchedi Galois Equivariant Étale RealizationThomas Geisser Relating Tate’s conjecture and the finiteness of the Tate–
Shafarevich groupKatharina Hübner Aspherical neighborhoods on arithmetic surfacesMoritz Kerz Algebraic K-theory and descent for blow-ups IIOliver Röndigs Computations of stable homotopy groups of motivic spheres
over a fieldRobert Kucharczyk Topological models for absolute Galois groupsDaniel Litt Integral Aspects of Fundamental GroupsFabien Morel Etale and motivic variation on Smith’s theory on action of
finite cyclic groupsBaptiste Morin On ζ-values of arithmetic schemesPaul Arne Østvaer Motivic Landweber exact theories and etale cohomologyTomer Schlank Homotopical Obstructions and the unramified Inverse Ga-
lois problemJohannes Schmidt Gabber’s geometric presentation lemma over henselian dis-
crete valuation ringsFlorian Strunk Algebraic K-theory and descent for blow-ups IKirsten Wickelgren Motivic Euler numbers and an arithmetic count of the lines
on a cubic surface
Heidelberg, 12.10.2017
Alexander Schmidt
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Report of the Workshop
Motivic and equivariant homotopy theory
as part of the DFG-SPP 1786
Organizers: Martin Frankland, Toan Nguyen, Konrad Voelkel (Osnabruck)Location: Universitat Osnabruck, Germany.Date: October 4th-7th, 2017.Overview: The workshop consists of two plenary lecture series of 3h45 each on motivic
and equivariant homotopy theory, a minicourse on algebraic geometry related to equivari-ant and motivic situations, three 1-hour research talks and three contributed 20-minutetalks.
As the title suggests, the goal of the workshop is to bring young researcher workingon motivic and equivariant homotopy theory closer together. There were 37 participantsfrom many countries attending the workshop. Participants were very active with manyquestions and disussions during the workshop. In the end, many significant and subtleinteractions between equivariant and motivic homotopy have been revealed. Researchersfrom each community have learned and exchanged techniques and ideas from the other.We have received very good feedbacks from all participants and were expected to organizethis kind of event in the near future.
Speakers:
Markus Spitzweck (Osnabruck)
Oliver Rondigs (Osnabruck)
Simon Pepin Lehalleur (Berlin)
Holger Brenner (Osnabruck)
Irakli Patchkoria (Bonn)
Matthias Wendt (Freiburg)
Emanuele Dotto (Bonn)
Olivier Haution (Munchen)
Magdalena Kedziorek (EPF Lausanne)
Bogdan Gheorghe (Bonn)
Benjamin Bohme (Copenhagen)
Christian Wimmer (Bonn)Funding: The workshop received in total 2519 Euro from the DFG-SPP 1786 to cover
accommodation for 9 participants who are PhD students and young postdocs.Other fundings: Oliver Rondigs’s research grant spent 3100 Euro to cover accom-
modation for 4 participants and travel expenses for 13 participants.The workshop received 4800 Euro from the DFG-GK 1916 to cover hotel, travel ex-
penses for invited speakers and other costs supporting the workshop (printings, papers,drinks, cookies, etc.,).
Participants:
1. Absmeier, Dominik Ruhr-Universitat-Bochum
2. Arndt, Peter Universitat Dusseldorf
3. Bohme, Benjamin University of Copenhagen
4. Brenner, Holger Universitat Osnabruck
5. Davies, Jack Universitat Bonn
6. Dotto, Emanuele Universitat Bonn
7. Ergus, Aras EPF Lausanne
8. Frankland, Martin Universitat Osnabruck
9. Gheorghe, Bogdan Max Planck Institute
10. Guzman, Gabriela Universitat Duisburg-Essen
11. Harrer, Daniel Universitat Duisburg-Essen
12. Haution, Olivier LMU Munchen
13. Heine, Hadrian Universitat Osnabruck
14. Hekking, Jeroen KTH Stockholm
15. Huisman, Johannes University of Brest
16. Kedziorek, Magdalena EPF Lausanne
17. Kumar, K. Arun Universitat Osnabruck
18. Kylling, Jonas Irgens University of Oslo
19. Masuda, Naruki University of Tokyo
20. Nguyen, Manh Toan Universitat Osnabruck
21. Nielsen, Espen Auseth University of Copenhagen
22. Nikandros, Nikitas Utrecht University
23. Patchkoria, Irakli Universitat Bonn
24. Pauli, Sabrina University of Oslo
25. Pepin-Lehalleur, Simon FU Berlin
26. Pham, Viet-Cuong University of Strasbourg
27. Pirashvili, Ilia Universitat Osnabruck
28. Ravi, Charanya University of Oslo
29. Romeo, P G Cochin University, Kerala, India
30. Rondigs, Oliver Universitat Osnabruck
31. Speirs, Martin University of Copenhagen
32. Spitzweck, Markus Universitat Osnabruck
33. Voelkel, Konrad Universitat Osnabruck
34. Wendt, Matthias Universitat Freiburg
35. Wimmer, Christian University of Bonn
36. Yamoul, Hicham University of Hassan II, Casablanca, Morocco
37. Yang, Xuan-Gottfried Independent Researcher