Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the viability of m**2 phi**2 and natural inflation   In the context of single field inflation, models with a quadratic potential
and models with a natural potential with subplanckian decay constant are in
tension with the Planck data. We show that, when embedded in a two-field model
with an additional super massive field, they can become consistent with
observations. Our results follow if the inflaton is the phase of a complex
field (or an angular variable) protected by a mildly broken U(1) symmetry, and
the radial component, whose mass is much greater than the Hubble scale, is
stabilized at subplanckian values. The presence of the super massive field,
besides modifying the effective single field potential, causes a reduction in
the speed of sound of the inflaton fluctuations, which drives the prediction
for the primordial spectrum towards the allowed experimental values. We discuss
these effects also for the linear potential, and show that this model increases
its agreement with data as well

8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an