Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can modified gravity explain accelerated cosmic expansion?   We show that the recently suggested explanations of cosmic acceleration by
the modification of gravity at small curvature suffer violent instabilities and
strongly disagree with the known properties of gravitational interactions.

33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph