Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Intrinsic time in Friedmann-Robertson-Walker universe   A global intrinsic time in Friedmann - Robertson - Walker models is
proportional to a scaling factor of the spatial metric. The aim of the paper is
to study an applicability of the intrinsic global time chosen to nearest
non-symmetric cases by taking into account linear metric perturbations. Scalar
linear perturbations add some corrections to the effective energy density in
the Hubble law. The metric vector and tensor perturbations in linear
approximation do not influence the intrinsic time.

18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs