Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: DM particles: how warm they can be?   One of important questions concerning particles which compose the Dark Matter
(DM) is their average speed. We consider the model of relativistic weakly
interacting massive particles and try to impose an upper bound on their actual
and past warmness through the analysis of density perturbations and comparison
with the LSS data. It is assumed that the DM can be described by the recently
invented model of reduced relativistic gas (RRG). The equation of state of the
RRG model is closely reproducing the one of the Maxwell distribution, while
being much simpler. This advantage of the RRG model makes our analysis very
efficient. As a result we arrive at the rigid and model-independent bound for
the DM warmness without using the standard (much more sophisticated) approach
based on the Einstein-Boltzmann system of equations.

11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph