Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Study of General Relativity and $f(R)$ Modified Gravity with
  Cosmological Constant for Einstein and Jordan Frames
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn