All Questions
8
questions
1
vote
1
answer
125
views
What if gravitation was the only force? [closed]
This is a follow up of Interactions within constituents of dark matter .
I wonder about dark matter, and, naturally, compare it with our observable world.
If gravitation would be the only force acting ...
- 1,028
1
vote
3
answers
145
views
Why doesn't frozen-out dark matter annihilate later during structure formation?
The so-called freeze-out of dark matter is based on a homogeneous description. However, in the later stages of the universe, where structures form, it seems very likely that the reaction rate would ...
- 619
1
vote
0
answers
84
views
The 'core-cusp' problem for dark matter halos in larger galaxies
TLDR: Do observations of larger galaxies favour 'cuspy' dark matter halo distributions, as predicted by N-body simulations?
I've been trying to understand the 'core-cusp' problem for dark matter halos ...
- 11
0
votes
0
answers
50
views
Is the $σ8$ tension in the ΛCDM cosmology evidence that the amount of Dark Matter (DM) in the universe is increasing?
Strong evidence is provided by recent cosmological studies that “clumpiness” in the large scale structure (LSS), as measured by $σ8$, is decreasing (for example, “Hyper Suprime-Cam Year 3 Results…”, X....
- 11
1
vote
1
answer
348
views
Which decoupled first? The dark matter or the CMB photons?
According theories that work best for the structure formation which happened first in the history of the evolution of the Universe, the decoupling of dark matter or the decoupling of photons? How sure ...
- 26.8k
1
vote
1
answer
147
views
What size of object does the peak of the cosmological power spectrum correspond to?
The title almost says it all, but to flesh it out more, what is the size a sphere corresponding to the peak in the cosmological power spectrum (Figure 2: https://ned.ipac.caltech.edu/level5/Sept11/...
- 531
4
votes
1
answer
208
views
What sets the lower mass limit for dark matter dominated structures?
Large galaxies appear to be dominated by dark matter, as do dwarf spheroidal galaxies with masses of perhaps $10^6 {\rm M}_{\odot}$. But (as far as I'm aware) there is no evidence for dark matter in ...
- 133k
1
vote
2
answers
439
views
Large scale structure of the universe
I have read of two seemingly straightforward explanations that give reasons for the inhomogeneity of the large-scale structure of the universe (i.e. why stars / galaxies formed where they did)
One is ...
- 1,059