All Questions
29
questions
2
votes
0
answers
90
views
Gravitational halos made of neutrinos...?
I have been recently interested in how halos made of standard model particles could be formed and behave.
After asking some questions in this site, I was told about how neutrinos could form such halos....
- 2,462
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
1
answer
183
views
Does NFW profile work for any galaxy?
We use Navarro–Frenk–White (NFW) to calculate Dark Matter (DM) density. Can we use it for DM halo in any galaxy or is it used only for Milky Way (MW)?
- 11
0
votes
1
answer
114
views
How to test for possible negative mass of dark matter?
What is the phenomenology of how to test if dark matter has possibly a negative mass (WP negative mass) in particle physics experiments, cosmology or astrophysics?
I lately came across this ...
- 4,170
1
vote
1
answer
75
views
How can we calculate formula for effective coupling constant in spin independent direct detection of dark matter?
At tree level, the spin independent
(SI) direct-detection cross section includes effective coupling constant. How to calculate effective coupling constant?
There is always a mandelstram variable in it....
- 7
0
votes
4
answers
184
views
Gondolo-Gelmini Change of Variables
In the article Cosmic abundances of stable particles: Improved analysis, P. Gondolo and G. Gelmini, Nucl. Phys. B 360 (1991), p. 145-179, they convert $\rm{d}^3p_1\rm{d}^3p_2=2\pi^2p_1p_2\rm{d}E_1\rm{...
6
votes
0
answers
163
views
Fermilab's results and a fifth force [duplicate]
On today's news, it says that Fermilab have done measurements on the spin of muons and that they are measured to wobble faster than expected according to current physics theories.
Apparently this may ...
- 13.7k
1
vote
0
answers
45
views
Possibility of reaching equilibrium starting with a nonequilibrium initial condition in the early radiation-domination
Update after @knzhou's comment
If in a theory, the coupling of the dark matter (DM) field to the Standard Model (SM) fields is small enough, the rate of interaction of the DM particles in the ...
- 26.8k
2
votes
2
answers
85
views
Research in next decade on dark matter: sky surveys vs particle detectors
The next decade is very promising for cosmology as new surveys such as SPHEREx, Roman, Euclid, DESI which will shed light on inflation, dark matter/energy and more. At the same time there are particle ...
- 4,576
1
vote
0
answers
28
views
Why are axions considered cold dark matter? [duplicate]
Why are axions considered cold dark matter? They have a very low mass and if I'm not wrong they decouple before BBN, and in some models even earlier than neutrinos, they they should definitely be ...
- 505
3
votes
1
answer
157
views
Dark Matter Abundance and Being a Cold Relic
I was reading Longair its stated that,
"An important conclusion was that, if dark matter particles were as common as neutrinos and photons,their rest mass energies could not be much greater than $...
- 3,122
0
votes
1
answer
51
views
How are neutrinos massless? Could they or at least some of their forms be a potential candidate for Dark matter? [duplicate]
I am particularly new to this subject. Can neutrino physics be understood by a 10th grade?
- 1
0
votes
1
answer
91
views
What is the possible relevance of $R$-parity to dark matter?
So say if $R$-parity is preserved, then whatever particle (if we assume its a particle) the dark matter consists of, only interacting with the weak nuclear force and gravitational, then wouldn't this ...
2
votes
2
answers
309
views
How do you distinguish between missing momentum from a neutrino and from dark matter?
I thought googling this would give me an answer quite quickly, but actually couldn't find much, so maybe it's a silly question. But I read that dark matter searches rely on measuring missing momentum ...
- 979
0
votes
1
answer
201
views
Are pressureless, collisionless and self-interacting dark matter all synonymous?
Is there any distinction between pressureless, collisionless and self-interacting dark matter or does being one imply the other?
- 26.8k