Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Palatini inflation in models with an $R^2$ term   The Starobinsky model, considered in the framework of the Palatini formalism,
in contrast to the metric formulation, does not provide us with a model for
inflation, due to the absence of a propagating scalar degree of freedom that
can play the role of the inflaton. In the present article we study the Palatini
formulation of the Starobinsky model coupled, in general nonminimally, to
scalar fields and analyze its inflationary behavior. We consider scalars,
minimally or nonminimally coupled to the Starobinsky model, such as a quadratic
model, the induced gravity model or the standard Higgs-like inflation model and
analyze the corresponding modifications favorable to inflation. In addition we
examine the case of a classically scale-invariant model driven by the
Coleman-Weinberg mechanism. In the slow-roll approximation, we analyze the
inflationary predictions of these models and compare them to the latest
constraints from the Planck collaboration. In all cases, we find that the
effect of the $R^2$ term is to lower the value of the tensor-to-scalar ratio.

26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
3
The categories of this paper are: physics