Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy-momentum tensor and helicity for gauge fields coupled to a
  pseudo-scalar inflaton   We study the energy-momentum tensor and helicity of gauge fields coupled
through $g \phi F \tilde{F}/4$ to a pseudo-scalar field $\phi$ driving
inflation. Under the assumption of a constant time derivative of the background
inflaton, we compute analitically divergent and finite terms of the energy
density and helicity of gauge fields for any value of the coupling $g$. We
introduce a suitable adiabatic expansion for mode functions of physical states
of the gauge fields which correctly reproduces ultraviolet divergences in
average quantities and identify corresponding counterterms. Our calculations
shed light on the accuracy and the range of validity of approximated analytic
estimates of the energy density and helicity terms previously existed in the
literature in the strongly coupled regime only, i.e. for $g \dot \phi/(2H) \gg
1$. We discuss the implications of our analytic calculations for the
backreaction of quantum fluctuations onto the inflaton evolution.

2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
1
The categories of this paper are: cs