Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resonant backreaction in axion inflation   Axion inflation entails a coupling of the inflaton field to gauge fields
through the Chern-Simons term. This results in a strong gauge field production
during inflation, which backreacts on the inflaton equation of motion. Here we
show that this strongly non-linear system generically experiences a resonant
enhancement of the gauge field production, resulting in oscillatory features in
the inflaton velocity as well as in the gauge field spectrum. The gauge fields
source a strongly enhanced scalar power spectrum at small scales, exceeding
previous estimates. For appropriate parameter choices, the collapse of these
over-dense regions can lead to a large population of (light) primordial black
holes with remarkable phenomenological consequences.

24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics