Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multicomponent perfect fluid with variable parameters in n Ricci-flat
  spaces   D-dimensional cosmological model describing the evolution of a multicomponent
perfect fluid with variable barotropic parameters in n Ricci-flat spaces is
investigated. The equations of motion are integrated for the case, when each
component possesses an isotropic pressure with respect to all spaces. Exact
solutions are presented in the Kasner-like form. Some explicit examples are
given: 4-dimensional model with an isotropic accelerated expansion at late
times and (4+d)-dimensional model describing a compactification of extra
dimensions.

18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex