Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modified gravity with negative and positive powers of the curvature:
  unification of the inflation and of the cosmic acceleration   The modified gravity, which eliminates the need for dark energy and which
seems to be stable, is considered. The terms with positive powers of the
curvature support the inflationary epoch while the terms with negative powers
of the curvature serve as effective dark energy, supporting current cosmic
acceleration. The equivalent scalar-tensor gravity may be compatible with the
simplest solar system experiments.

10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
2
The categories of this paper are: math
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga