Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Behavior of $F(R)$ gravity around a crossing of the phantom divide   We study a model of $F(R)$ gravity in which a crossing of the phantom divide
can be realized. In particular, we demonstrate the behavior of $F(R)$ gravity
around a crossing of the phantom divide by taking into account the presence of
cold dark matter.

11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga