Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A conformal approach for the analysis of the non-linear stability of
  pure radiation cosmologies   The conformal Einstein equations for a tracefree (radiation) perfect fluid
are derived in terms of the Levi-Civita connection of a conformally rescaled
metric. These equations are used to provide a non-linear stability result for
de Sitter-like tracefree (radiation) perfect fluid
Friedman-Lema\^{\i}tre-Robertson-Walker cosmological models. The solutions thus
obtained exist globally towards the future and are future geodesically
complete.

32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat