Related papers: Phase Transition Generated Cosmological Magnetic F…
We provide a new bound on the amplitude of primordial magnetic fields (PMFs) by using a novel mechanism, named {\it magnetic reheating}. Before the epoch of recombination, PMFs induce the fluid motions in a photon-baryon plasma through the…
We study the generation and evolution of density perturbations and peculiar velocities due to primordial magnetic fields. We assume that a random magnetic field was present before recombination and follow the field's effect on the baryon…
In this paper we study the effect of a magnetic field on the fluctuation spectrum of the cosmic microwave background. We find that upcoming measurements might give interesting bounds on large scale magnetic fields in the early Universe. If…
In this paper, we propose a mechanism to generate large-scale magnetic fields with correlations lengths of 100 kpc. Domain walls with QCD scale internal structure form and coalesce obtaining Hubble size correlations and align nucleon spins.…
Weak magnetic fields must have existed in the early Universe, as they were sourced by the cross product of electron density and temperature gradients through the Biermann-battery mechanism. In this paper we calculate the magnetic fields…
Primordial magnetic fields (PMFs) create a large squeezed-type non-Gaussianity in tensor perturbation, which generates non-Gaussian temperature fluctuations in the cosmic microwave background (CMB). We for the first time derive an…
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…
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 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…
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…
The effects of magnetic fields on Big Bang Nucleosynthesis(BBN) have been calculated, and the impact on the abundances of the light elements have been investigated numerically. An upper limit on the strength of primordial magnetic fields…
We present a mechanism for generating primordial magnetic fields with large correlation lengths on the order of 100 kpc today. The mechanism is based on recently conjectured QCD domain walls or similar CP violating domain walls with QCD…
Primordial magnetic fields (PMFs) enhance small-scale structure formation through the Lorentz force acting on baryons, boosting the abundance of low-mass halos and their hosted galaxies. We show that the reionisation history calibrated with…
We discuss the implications of causality on a primordial magnetic field. We show that the residual field on large scales is much more suppressed than usually assumed and that a helical component is even more reduced. Due to this strong…
Magnetic fields appear to be present in all galaxies and galaxy clusters. Recent measurements indicate that a weak magnetic field may be present even in the smooth low density intergalactic medium. One explanation for these observations is…
Magnetic fields appear to be present in essentially all astrophysical environments, including galaxies, clusters of galaxies and voids. There are both observational and theoretical motives for considering the possibility of their origin…
A primordial stochastic magnetic field will induce temperature and polarization fluctuations in the cosmic microwave background. We outline a calculation of the resulting fluctuation power spectra and present numerical results.
We propose a mechanism for the generation of magnetic fields on cosmological scales that is operative after recombination. An essential ingredient is an instability (of parametric resonance type) of the electromagnetic field driven by an…
Primordial magnetic fields could provide an explanation for the galactic magnetic fields observed today, in which case they may also leave interesting signals in the CMB and the small-scale matter power spectrum. We discuss how to…
In this thesis, we aim to investigate the mechanisms underlying the genesis of magnetic fields in the Universe and explore their potential in addressing the matter-antimatter asymmetry. We construct consistent models that generate the…