Related papers: Preheating - cosmic magnetic dynamo ?
In this paper, we discussed the multiple vector fields during the inflation era and the inflationary magnetogenesis with multiple vector fields. Instead of a single coupling function in single vector field models, the coupling matrix…
Certain inflationary models can feature periods of preheating - an era preceding reheating during which parametric resonance triggers an exponential production of bosons. This non-perturbative process can have significant impact on the…
Spontaneous magnetic field generation plays important role in laser-plasma interactions. Strong quasi-static magnetic fields affect the thermal conductivity and the plasma dynamics, particularly in the case of ultra intense laser where the…
We discuss a model which can generate scale-invariant helical magnetic fields on large scales ($\lesssim 1$Mpc) in the primordial universe. It is also shown that the electric conductivity becomes significant and terminates magnetogenesis…
We discuss how gravitational waves could amplify seed magnetic fields to strengths capable of supporting the galactic dynamo. We consider the interaction of a weak magnetic field with gravity wave distortions in almost FRW cosmologies and…
We propose a new mechanism for magnetic field generation from inflation, by which strong magnetic fields can be generated on cosmological scales. These fields may be observable by cosmic microwave background radition measurements, and may…
We consider inhomogeneous preheating in multi-field models of cosmological perturbation. After preheating, two fields are trapped at an enhanced symmetric point. One field is an oscillating field and the other is a light field that plays an…
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.…
Efficient acceleration of cosmic rays (via the mechanism of diffusive shock acceleration) requires turbulent, amplified magnetic fields in the shock's upstream region. We present results of multidimensional particle-in-cell simulations…
We study the backreaction problem in a mechanism of magnetogenesis from inflation. In usual analysis, it has been assumed that the backreaction due to electromagnetic fields spoils inflation once it becomes important. However, there exists…
Inflationary reheating via resonant production of non-minimally coupled scalar particles with only gravitational coupling is shown to be extremely strong, exhibiting a negative coupling instability for $\xi < 0$ and a wide resonance decay…
The dynamics of preheating after inflation has not been clearly understood yet.In particular, the issue of the generation of metric perturbations during preheating on super-horizon scale is still unsettled. Large scale perturbations may…
The changes in the cosmic microwave background (CMB) spectrum seen as an increase of temperature due to a strong magnetic field are determined and their influence on the polarization of the radiation is exhibited. The effect is due to the…
We investigate an intensification mechanism for the magnetic field near the base of the solar convection zone that does not rely on differential rotation. Such mechanism in addition to differential rotation has been suggested by studies of…
The interplay among the possible variation of gauge coupling and the inflationary dynamics is investigated in a simplified toy model. Depending upon various parameters (scalar mass, curvature scale at the end of inflation and at the onset…
The origin of large scale cosmological magnetic fields remains a mystery, despite the continuous efforts devoted to that problem. We present a new model of magnetic field generation, based on local charge separation provided by an…
We investigate the effects of local features in the inflationary potential on the preheating dynamics after inflation. We show that a small feature in the potential can enhance the resonance and bring the radiation-like state equation…
Metric perturbations typically strengthen field resonances during preheating. In contrast we present a model in which the super-Hubble field resonances are completely {\em suppressed} when metric perturbations are included. The model is the…
The existence of large-scale anisotropy can not be ruled out by the cosmic microwave background (CMB) radiation. Over the years, several models have been proposed in the context of anisotropic inflation to account for CMB's cold spot and…
We study the evolution of primordial magnetic fields in an expanding cosmic plasma. For this purpose we present a comprehensive theoretical model to consider the evolution of MHD turbulence that can be used over a wide range of physical…