相关论文: Void magnetic field and its primordial origin in i…
A short introduction to structure formation is given, followed by a discussion of the possible characteristics of the initial perturbations assuming a generic inflationary origin. Observational data related to large-scale structure and the…
Observations of $\gamma$-ray from blazars suggest the presence of magnetic fields in the intergalactic medium, which may require a primordial origin. Intense enough primordial magnetic fields can arise from theories of dynamical electroweak…
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 study the primordial magnetic field generated by stochastic currents produced by scalar charged particles created at the beginning of the radiation dominated epoch. We find that for the mass range 10^(-6)GeV \leq m \leq 10^2 GeV, a field…
High-scale string inflationary models are in well-known tension with low-energy supersymmetry. A promising solution involves models where the inflaton is the volume of the extra dimensions so that the gravitino mass relaxes from large…
We present a simplified model in which we suggest that two important galactic problems -the magnetic field configuration at large scales and the flat rotation curve- may be simultaneously explained. A highly convective disc produces a high…
Magnetic fields are present on all scales in the Universe. While we understand the processes which amplify the fields fairly well, we do not have a "natural" mechanism to generate the small initial seed fields. By using fully relativistic…
The magnetogenesis scenarios triggered by the early variation of the gauge coupling are critically analyzed. In the absence of sources, it is shown that the electric and magnetic power spectra can be explicitly computed by means of…
Mechanisms of generation of magnetic fields in the early universe which could seed the present-day large scale galactic magnetic fields, are briefly reviewed. Three possible ways to create large scale magnetic fields are discussed: breaking…
The existence of magnetic fields associated with the intracluster medium in clusters of galaxies is now well established through different methods of analysis. The most detailed evidence for the presence of cluster magnetic fields comes…
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…
We explore the generation of large-scale magnetic fields from inflation in teleparallelism, in which the gravitational theory is described by the torsion scalar instead of the scalar curvature in general relativity. In particular, we…
Primordial magnetogenesis is an intriguing possibility to explain the origin of intergalactic magnetic fields (IGMFs). However, the baryon isocurvature problem has recently been pointed out, ruling out all magnetogenesis models operating…
We review the literature concerning how the cosmic magnetic fields pervading nearly all galaxies actually got started. some observational evidence involves the chemical abundance of the light elements Be and B, while another one is based on…
Observations of stable mainly dipolar magnetic fields at the surface of ~7% of single hot stars indicate that these fields are of fossil origin, i.e. they descend from the seed field in the molecular clouds from which the stars were formed.…
We clarify the causal structure of an inflating magnetic monopole. The spacetime diagram shows explicitly that this model is free from ``graceful exit'' problem, while the monopole itself undergoes ``eternal inflation''. We also discuss…
We review our current understanding of galactic dynamo theory, paying particular attention to numerical simulations both of the mean-field equations and the original three-dimensional equations relevant to describing the magnetic field…
Despite their ubiquity, the origin of cosmic magnetic fields remains unknown. Various mechanisms have been proposed for their existence including primordial fields generated by inflation, or amplification and injection by compact…
Spontaneous breaking of Lorentz invariance may take place in string theories, possibly endowing the photon with a mass. This leads to the breaking of the conformal symmetry of the electromagnetic action allowing for the generation within…
Inflation is the leading paradigm for explaining the origin of primordial density perturbations and the observed temperature fluctuations of the cosmic microwave background. However many open questions remain, in particular whether one or…