large-scale structure with interacting dark matter and dark energy
DESCRIPTION
Large-Scale Structure with Interacting Dark Matter and Dark Energy. Paul Matthew Sutter University of Illinois at Urbana-Champaign. (Sutter and Ricker, 2006). With: Paul Ricker, Ben Wandelt, and Greg Huey. The Conundrum of Concordance. Playbill. Essential Problem: - PowerPoint PPT PresentationTRANSCRIPT
PASCOS '06 at OSUApril 20, 2023
Large-Scale Large-Scale Structure with Structure with
Interacting Interacting Dark Matter Dark Matter
and Dark Energyand Dark Energy
Paul Matthew SutterUniversity of Illinois at Urbana-Champaign
With:Paul Ricker, Ben Wandelt, and Greg Huey
(Sutter and Ricker, 2006)
PASCOS '06 at OSUApril 20, 2023
Completely Unknown
75%
Somewhat unknown
4%
Largely Unknown
21%
The Conundrum of ConcordanceThe Conundrum of Concordance
PASCOS '06 at OSUApril 20, 2023
PlaybillPlaybill
Essential Problem:Explain “coincidence” of dark matter (DM) and dark energy (DE)
Essential Solution:Coincidence? Anthropic selection? Or allow DM and DE to interact!
Previous Work:Farrar & Peebles (2004) develop theoretical model (summarized
soon)F&P examine H(t), linear effects, etc.; able to reject some models Nusser et al. (2005) do limited simulations involving screened
potential
What we’re after:Fully realize F&P’s dynamics in N-body simulations of cluster growthOpen up parameter space and explore large-scale consequences
“Are the various models distinguishable?”“If so, where should we look?”
PASCOS '06 at OSUApril 20, 2023
Introducing the Players…Introducing the Players…
•A scalar field responsible for the dark energy:
•A dark matter particle family with field-dependent mass:
•Doing usual perturbation theory:
)(2
1 ,,
4 VgxdSDE
i
DM
dsy
yigxdSi
*
*4 )(
)(),(
),()(
1
1
ttx
txt
b
b
(Farrar & Peebles, 2004)
0let
1
*
DMv
Taking classical limit
PASCOS '06 at OSUApril 20, 2023
The Major Story ArcsThe Major Story Arcs
Get the following Equations of Motion:
•DM particle:
•DE background field:
•DE perturbation field:
)(
1 1
taa
a
bb
b
vv
0)(
1
8
3)(3 3
0
20 a
tGH
d
dV
a
am
bbb
byna 21
2 /
PASCOS '06 at OSUApril 20, 2023
Interactions & DialoguesInteractions & Dialogues
Modifications to standard cosmology:
)(
1 1
taa
a
bb
b
vv
A new Friedmann equation:
)(
2
1
3
82
3
0
20
2
Vdt
dGaH
a
am
An additional term in DM EoM
A time-dependent DM particle mass
A fifth force!
25 )(
1
tF th
PASCOS '06 at OSUApril 20, 2023
Backstage…Backstage…
Using a customized version of FLASH, an Adaptive Mesh Refinement (AMR) tool for astrophysics and cosmology.
FLASH uses a multigrid particle-mesh algorithm.
Simulation parameters:
•64 Mpc/h cubic box•256^3 particles •256^3 mesh•No AMR•z=50 to z=0•
Halos are found with FoF method:
•1/5 grid maximum linking distance
•3000 particle minimum in halos71.0,7.0,0.0,3.0 hbm
(Fryxell et al., 2000)
PASCOS '06 at OSUApril 20, 2023
Potential for a HitPotential for a Hit
Example: a power-law potential: /)( KV
PASCOS '06 at OSUApril 20, 2023
……Or Tragedy?Or Tragedy?
Attempt to fit our radial density profiles to the
NFW profile:
21
)(
ss
s
crit rrrr
r
(Navarro, Frenk, White, 1997)
Happens in all models…
YIKES!!Need more resolution…
PASCOS '06 at OSUApril 20, 2023
The SequelsThe Sequels
These results are preliminary, but suggestive!Good: get mass functions consistent with standard
cosmologiesBad: get mass functions consistent with standard cosmologies
Ugly: resolution too poor to resolve cores
What we’re working on:• Larger grids with AMR (currently queued at NCSA)
• More detailed statistical analysis• Time-evolution of halo structure
• Other linear potentials• Multiple DM particle families• Non-perturbative methods
Paper coming soon!