Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reconstructing cosmic acceleration from f(R) modified gravity   A variant of the accelerating cosmology reconstruction program is developed
for $f(R)$ gravity. Reconstruction schemes in terms of e-foldings and by using
an auxiliary scalar field are developed. An example of a model with a transient
phantom behavior without real matter is explicitly discussed in both schemes.
Detailed comparison of the two schemes of reconstruction is presented. It seems
to support physical non-equivalence of the two frames.

24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn