Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonsingular and accelerated expanding universe from effective Yang-Mills
  theory   The energy-momentum tensor coming from one-parameter effective Yang- Mills
theory is here used to describe the matter-energy content of the homogeneous
and isotropic Friedmann cosmology in its early stages. The behavior of all
solutions is examined. Particularly, it is shown that only solutions
corresponding to an open model allow the universe to evolve into an accelerated
expansion. This result appears as a possible mechanism for an inflationary
phase produced by a vector field. Further, depending on the value of some
parameters characterizing the system, the resulting models are classified as
singular or nonsingular.

29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn