Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scaling relations of the slightly self-interacting cold dark matter in
  galaxies and clusters   Recent observations in galaxies and clusters indicate dark matter density
profiles exhibit core-like structures which contradict to the numerical
simulation results of collisionless cold dark matter. The idea of
self-interacting cold dark matter (SICDM) has been invoked to solve the
discrepancies between the observations and numerical simulations. In this
article, I derive some important scaling relations in galaxies and clusters by
using the long-range SICDM model. These scaling relations give good agreements
with the empirical fittings from observational data in galaxies and clusters if
the dark matter particles are only slightly self-interacting. Also, there may
exist a universal critical optical depth $\tau_c$ that characterizes the
core-like structures. These results generally support the idea of SICDM to
tackle the long-lasting dark matter problem.

10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
3
The categories of this paper are: physics
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom