Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gravitoelectromagnetic inflation and seeds of cosmic magnetic fields
  from geometrical Weyl-invariant scalar-tensor theory of gravity   We investigate cosmological inflationary scenarios from a
gravitoelectromagnetic theory. Our work is formulated in the light of a
recently introduced geometrical Weyl-Invariant scalar-tensor theory of gravity,
where the nature of both the electromagnetic potential and the inflaton field
is attributed to the space-time geometry. We obtain a Harrison-Zeldovich power
spectrum for quantum fluctuations of the inflaton field. In our model the
electromagnetic fields have also a nearly scale invariant power spectrum for a
power-law inflation. We found that the the seed magnetic fields have a nearly
scale invariant power spectrum and generate in the present times cosmic
magnetic fields of the order $\lesssim 10^{9}$ gauss, in good agreement with
CMB observations.

21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
19
The categories of this paper are: eess