Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inflationary f(R) cosmologies   This paper discusses a simple procedure to reconstruct f (R)-gravity models
from exact cosmological solutions of the Einstein field equations with a
noninteracting classical scalar field-and-radiation background. From the kind
of inflationary scenario we want, we show how the potential functions can be
obtained. We then show how an f (R) gravitational Lagrangian density that
mimics the same cosmological expansion as the scalar field-driven inflation of
General Relativity can be reconstructed. As a demonstration, we calculate the
slow-roll parameters (the spectral index n s and the tensor-to-scalar ratio r)
and compare them to the Planck data.

1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph