相关论文: Evolution of Cosmological Perturbations in the Pre…

This paper investigates the possible cosmological implications of the presence of an antisymmetric tensor field related to a lack of commutatitivity of spacetime coordinates at the Planck era. For this purpose, such a field is promoted to a…

A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound $\sim 10^{-16}$ Gauss. Such magnetic fields can play an…

Forthcoming datasets from the Planck experiment and others are in a position to probe the CMB non-Gaussianity with higher accuracy than has yet been possible and potentially open a new window into the physics of the very early universe.…

A possible explanation for the origin of the magnetic fields observed today in matter structures is that they were generated in the primordial universe. After briefly revising the model of a primordial stochastic magnetic field and…

Large scale magnetic fields represent a triple point where cosmology, high-energy physics and astrophysics meet for different but related purposes. After reviewing the implications of large scale magnetic fields in these different areas,…

I describe the imprint of primordial magnetic fields on the CMB. I show that these are observable only if the field amplitude is of the order of $B\gsim 10^{-9}G$ on Mpc scale. I further argue that such fields are strongly constrained by…

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 consider the dynamics of electromagnetic fields in an almost-Friedmann-Robertson-Walker universe using the covariant and gauge-invariant approach of Ellis and Bruni. Focusing on the situation where deviations from the background model…

In this paper we show that noncommutativity in spatial coordinates can generate magnetic field in the early Universe on a horizon scale. The strength of such a magnetic field depends on the number density of massive charged particles…

It is well-known that first order phase transitions in the early universe can be a powerful source of observable stochastic gravitational wave backgrounds. Any such gravitational wave background must exhibit large-scale anisotropies at…

Prompted by the recent more precise determination of the basic cosmological parameters and growing evidence that the matter-energy content of the universe is now dominated by dark energy and dark matter we present the general solution of…

The origin of interstellar and intergalactic magnetic fields remains largely unknown. One possibility is that they are related to the primordial magnetic fields (PMFs) produced by, for instance, the phase transitions of the early Universe.…

We consider anisotropic magnetized cosmologies filled with conductive plasma fluid and study the implications of metric perturbations that propagate parallel to the ambient magnetic field. It is known that in the first order (linear)…

In view of several conflicting results, we reanalyze the effects of magnetic fields on the primordial nucleosynthesis. In the case the magnetic field is homogeneous over a horizon volume, we show that the main effects of the magnetic field…

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 consider the most general primordial cosmological perturbation in a universe filled with photons, baryons, neutrinos, and a hypothetical cold dark matter (CDM) component within the framework of linearized perturbation theory. We give a…

We present the newest statistical and numerical analysis of the matter and cosmic microwave background power spectrum with effects of the primordial magnetic field (PMF) included. New limits to the PMF strength and power spectral index are…

We compare the latest observations of Cosmic Microwave Background (CMB) Anisotropies with the theoretical predictions of the standard scenario of structure formation. Assuming a primordial power spectrum of adiabatic perturbations we found…

In the presence of the primordial magnetic field, initial vector (vorticity) perturbations produce cosmological Alfven waves and leave imprints on cosmic microwave background (CMB) temperature and polarization anisotropy. We have…

The CMB is a remarkably distortionless blackbody, and this strongly constrains the amount of energy that can have been injected at high redshift, thereby limiting the role that hydrodynamical amplification can have played in cosmic…