Related papers: Constraints on Primordial Magnetic Fields from Inf…
Generation of magnetic field during inflation can explain its presence over a wide range of scales in the Universe. In Ref.\cite{sharma2017}, we proposed a model to generate these fields during inflation. These fields have nonzero…
There are at present more then 30 theories about the origin of cosmic magnetic fields at galactic and intergalactic scales. Most of them rely on concepts of elementary particle physics, like phase transitions in the early Universe, string…
We investigate primordial magnetogenesis by assuming the gauge field is prepared in a thermal state during inflation rather than the standard Bunch-Davies vacuum. The temperature $\mathcal{T}$ introduces a physical scale that breaks…
This paper concerns the generation and evolution of the cosmological (large-scale $\sim Mpc$) magnetic fields in an inflationary universe. The universe during inflation is represented by de Sitter space-time. We started with the Maxwell…
We study the inflationary generation of helical cosmological magnetic fields in a higher-dimensional generalization of the electromagnetic theory. For this purpose, we also include a parity breaking piece to the electromagnetic action. The…
We consider models in which the (transverse) photon mass is non-zero during inflation and drops to zero non-adiabatically at the end of inflation. Through this process, vacuum fluctuations of the photon field are converted into physical,…
We describe a simple scenario of inflationary magnetogenesis based on a helical coupling to electromagnetism. It allows to generate helical magnetic fields of strength of order up to $10^{- 7}\,\text{G}$, when extrapolated to the current…
We consider the possibility of inflationary magnetogenesis due to dynamical couplings of the electromagnetic fields to gravity. We find that large primordial magnetic fields can be generated during inflation without the strong coupling…
Recent blazar observations provide growing evidence for the presence of magnetic fields in the extragalactic regions. While a natural speculation is to associate the production to inflationary physics, it has been known that magnetogenesis…
In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary…
Inflation has the potential to seed the galactic magnetic fields observed today. However, there is an obstacle to the amplification of the quantum fluctuations of the electromagnetic field during inflation: namely the conformal invariance…
The origin of the $\mu$G magnetic fields observed in galaxies is unknown. One promising scenario is that magnetic fields generated during inflation, larger than 0.1 nG on Mpc scales, were adiabatically compressed to $\mu$G strengths in…
Cosmological inflation provides the initial conditions for the structure formation. However, the origin of large-scale magnetic fields cannot be addressed in this framework. The key issue for this long-standing problem is the conformal…
Inflation has long been thought as the best way of producing primordial large-scale magnetic fields. To achieve fields strong enough to seed the galactic dynamo, most of the mechanisms operate outside conventional electromagnetic theory.…
We present preliminary results on the possible effects that primordial magnetic fields can have for a warm inflation scenario, based on global supersymmetry, with a new-inflation-type potential. This work is motivated by two considerations:…
Primordial magnetic fields (PMFs) are possible candidates for explaining the observed magnetic fields in galaxy clusters. Two competing scenarios of primordial magnetogenesis have been discussed in the literature: inflationary and…
We analyse the evolution of primordial magnetic fields in spatially flat Friedmann universes and reconsider the belief that, after inflation, these fields decay adiabatically on all scales. Without~abandoning classical electromagnetism or…
Inflationary magnetogenesis has long been assumed to be the most promising mechanism for producing large-scale magnetic fields in our universe. However, generically, such models are plagued with either backreaction or strong coupling…
The most studied mechanism of inflationary magnetogenesis relies on the time-dependence of the coefficient of the gauge kinetic term $F_{\mu\nu}\,{F}^{\mu\nu}$. Unfortunately, only extremely finely tuned versions of the model can…
The generation of large-scale magnetic fields is studied in inflationary cosmology. We consider the violation of the conformal invariance of the Maxwell field by dilatonic as well as non-minimal gravitational couplings. We derive a general…