Related papers: Large-scale magnetic fields from inflation in dila…
We study inflation and entropy generation in a recently proposed pre-big-bang model universe produced in a collision of gravitational and dilaton waves. It is shown that enough inflation occurs provided the incoming waves are sufficiently…
We study the generation of electromagnetic fields in a string-inspired scenario associated with a rolling massive scalar field $\phi$ on the anti-D3 branes of KKLT de Sitter vacua. The 4-dimensional DBI type effective action naturally gives…
The power spectrum of the cosmic microwave background from both the Planck and WMAP data exhibits a slight dip in for multipoles in the range of l=10-30. We show that such a dip could be the result of resonant creation of a massive particle…
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…
We argue that if axions are the dark matter, their coupling to electromagnetism results in exponential growth of a helical magnetic field when the axion field first rolls down its potential. After an inverse cascade, the relevant length…
In the framework of Higgs inflation, we consider the electromagnetic field nonminimally coupled to gravity via the parity-preserving $\propto RF^{2}$ and parity-violating $\propto RF\tilde{F}$ terms. Using the perturbation theory to the…
Since magnetic fields in galaxies, galactic clusters and even void regions are observed, theoretical attempts to explain their origin are strongly motivated. It is interesting to consider that inflation is responsible for the origin of the…
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…
Detailed physical processes of magnetic field generation from density fluctuations in the pre-recombination era are studied. Solving Maxwell equations and the generalized Ohm's law, the evolutions of the net charge density, the electric…
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…
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 numerically study the interaction of inflation-produced magnetic fields with gravitational waves, both of which originate from quantum fluctuations during inflation. The resonance between the magnetic field perturbations and the…
Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments…
We present a five dimensional unified theory of gravity and electromagnetism which leads to modified Maxwell equations, suggesting a new origin for galactic magnetic fields. It is shown that a region with nonzero scalar curvature would…
We explore the possibility of generating large-scale magnetic fields from second-order cosmological perturbations during the pre-recombination era. The key process for this is Thomson scattering between the photons and the charged particles…
The Kelvin-Helmholtz instability in an ionized plasma is considered with a focus on the generation of magnetic field via the Biermann battery mechanisms. The problem is studied through direct numerical simulations of two counter-directed…
We consider possible geometries of magnetic fields in GRB outflows, and their evolution with distance from the source. For magnetically driven outflows, with an assumed ratio of magnetic to kinetic energy density of order unity, the field…
We study the generation of helical magnetic fields in a model of inflationary magnetogenesis which is free from the strong coupling and back-reaction problems. To generate helical magnetic fields, we add an $f^2 \tilde{F}^{\mu\nu}…
In the framework of chaotic inflation we study the case of a massive scalar field using a semiclassical approach. We derive the energy density fluctuations in the infrared sector generated by matter field and gauge-invariant metric…
Following Prendergast we study the relativistically expanding electromagnetic fields generated by an axisymmetric explosion of magnetic energy in a small volume. The magnetic field expands uniformly either within a cone or in all directions…