Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analytical solutions for cosmological perturbations in a one-component
  universe with shear stress   We construct explicit solutions for scalar, vector and tensor perturbations
in a less known setting, a flat universe filled by an isotropic elastic solid
with pressure and shear modulus proportional to energy density. The solutions
generalize the well known formulas for cosmological perturbations in a universe
filled by ideal fluid.

25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics