Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self consistent estimates of magnetic fields from reheating   We investigate the generation of primordial magnetic fields from stochastic
currents created by the cosmological transition from inflation to reheating. We
consider N charged scalar fields coupled to the electromagnetic field in a
curved background and derive self-consistent equations for the evolution of the
two point functions of the fields, which in the large N limit give a decoupled
set for the scalar and the electromagnetic functions. The main contribution to
the electric current comes from the infrared portion of the spectrum of created
particles, and in this limit the damping of the magnetic field is not due to
normal conductivity but to London currents in the scalar field. For a given set
of the physical parameters of the problem, we solved this equation numerically
and found that, due to the fact that the London currents are oscillating, the
field actually grows exponentially during the time interval in which our
large-N limit equations are valid. Although for the chosen parameters the
induced field is weak, the present uncertainties on their actual values leave
open the possibility for higher intensities.

24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex