Related papers: Limits on possible magnetic fields at nucleosynthe…
We show that the presence of primordial stochastic (hypercharge) magnetic fields before the electroweak (EW) phase transition induces isocurvature fluctuations (baryon number inhomogeneities). Depending on the details of the magnetic field…
We study the impacts of magnetic field on the neutrino transport inside core-collapse supernovae (CCSNe). Magnetic field quantizes the momentum of electrons and positrons, resulting in the modification of weak-interaction cross sections and…
If massive neutrinos possess magnetic moments, they can undergo spin flip in a magnetic field. The magnetic fields needed for a meaningful measurement of neutrino moments could be very high and may occur in astronomical objects such as some…
Recent FERMI observations provide a lower limit of 10^{-15} G for the magnetic field strength in the intergalactic medium (IGM). This is consistent with theoretical expectations based on the Biermann battery effect, which predicts such IGM…
One of the fundamental properties of astrophysical magnetic fields is their ability to change topology through reconnection and in doing so, to release magnetic energy, sometimes violently. In this work, we review recent results on the role…
The net effect of the small scale magnetic field on the Sun's (bolometric) brightness is studied with realistic 3D MHD simulations. The direct effect of brightening within the magnetic field itself is consistent with measurements in…
We study the 21-cm differential brightness temperature in the presence of primordial helical magnetic fields for redshift $z=10-30$. We argue that the $\alpha$-effect that sets in at earlier time can be helpful in lowering the gas…
The broken-symmetry electroweak vacuum is destabilized in the presence of a magnetic field stronger than a critical value. Such magnetic field may be generated in the phase transition and restore the symmetry inside the bubbles. A numerical…
Observational limits on $y$- and $\mu$-type distortions can constrain properties of magnetic fields in the early universe. For a Gaussian, random, and non-helical field, $\mu$ and $y$ are calculated a function of the present-day strength of…
We calculate the effect of variation in the light-current quark mass, $m_q$, on standard big bang nucleosynthesis. A change in $m_q$ at during the era of nucleosynthesis affects nuclear reaction rates, and hence primordial abundances, via…
We study theoretically the magnetic field effect on a neutral, but polarizable exciton confined in quantum-ring structures. For excitons with a nonzero dipole moment, a novel magnetic interference effect occurs: The ground state of an…
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…
Incorporating microscopic nuclear-structure information into the discussion of bulk properties of astronomical objects such as neutron stars has always been a challenging issue in interdisciplinary nuclear astrophysics. Using the…
For neutrinos with a magnetic moment, we show that the collisions in a hot and dense plasma act as an efficient mechanism for the conversion of $\nu_L$ into $\nu_R$. The production rate for right-handed neutrinos is computed in terms of a…
We review the motivation for, lattice results on, and some implications of, external magnetic fields present at the time of the cosmological electroweak phase transition.
The radiative decay $\nu_H \to \nu_L + \gamma$ of massive neutrinos is analyzed in the framework of the standard model with lepton mixing for very strong magnetic fields $B\gg B_{cr} = m_e^2/e \sim 4.14 \times 10^{13}$G. The analysis is…
Magnetohydrodynamic turbulence drives the central engine of post-merger remnants, potentially powering both a nucleosynthetically active disk wind and the relativistic jet behind a short gamma ray burst. We explore the impact of the…
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…
Big Bang Nucleosynthesis can provide, via constraints on the expansion rate at that time, limits on possible variations in Newton's Constant, $G$. The original analyses were performed before an independent measurement of the…
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…