Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct Photons from Hot Quark Matter in Renormalized Finite-Time-Path
  QED   Within the finite-time-path out-of-equilibrium quantum field theory (QFT), we
calculate direct photon emission from early stages of heavy ion collisions,
from a narrow window, in which uncertainty relations are still important and
they provide a new mechanism for production of photons. The basic difference
with respect to earlier calculations, leading to diverging results, is that we
use renormalized QED of quarks and photons. Our result is a finite contribution
that is consistent with uncertainty relations.

28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc