相关论文: Thermal leptogenesis in anisotropic cosmology
We propose a novel leptogenesis mechanism with a temperature-dependent coupling between the right-handed neutrino and Standard Model particles. This coupling experiences suppression at high temperatures and becomes sizable when the lepton…
We analyze lepton asymmetry induced in the decay of right--handed neutrinos in a class of minimal left--right symmetric models. In these models, which assume low energy supersymmetry, the Dirac neutrino mass matrix is proportional to the…
For the Warm Dark Matter (WDM) cosmological model the implications of strongly inhomogenous, primordial baryon distribution on sub-galactic scales for Big Bang Nucleosynthesis, Cosmic Microwave Background anisotropies and Galaxy Formation…
We study a homogeneous and nearly-isotropic Universe permeated by a homogeneous magnetic field. Together with an isotropic fluid, the homogeneous magnetic field, which is the primary source of anisotropy, leads to a plane-symmetric Bianchi…
Thermal leptogenesis, in the framework of the standard model with three additional heavy Majorana neutrinos, provides an attractive scenario to explain the observed baryon asymmetry in the universe. It is based on the out-of-equilibrium…
Low-scale leptogenesis provides an economic and testable description of the origin of the baryon asymmetry of the Universe. In this scenario, the baryon asymmetry of the Universe is reprocessed from the lepton asymmetry by electroweak…
Various new physics models, e.g., theories of compositeness, can accommodate the color singlet excited leptons that interact with the leptons, quarks, leptoquarks, etc. A particular type of excited lepton, which at low energies interacts…
We propose a non-thermal scenario for the generation of baryon number asymmetry in a radiative neutrino mass model which is modified to realize inflation at the early Universe. In this scenario, inflaton plays a crucial role in both…
In this paper we introduce a LTB-Bianchi I (plane symmetric) model of Universe. We study and solve Einstein field equations. We investigate the effects of such model of Universe in particular these results are important in understanding the…
The present work is related to anisotropic cosmological evolution in metric $f(R)$ theory of gravity. The initial part of the paper develops the general cosmological dynamics of homogeneous anisotropic Bianchi-I spacetime in $f(R)$…
The possibility of generating the baryon asymmetry of the Universe via flavor oscillation in the early Universe is discussed. After the inflation, leptons are born in some states, travel in the medium, and are eventually projected onto…
The very recent Boomerang results give an estimate of unprecedented precision of the Cosmic Microwave Background anisotropies on sub--degree scales. A puzzling feature for theoretical cosmology is the low amplitude of the second acoustic…
We propose a baryogenenesis mechanism that uses a rotating condensate of a Peccei-Quinn (PQ) symmetry breaking field and the dimension-five operator that gives Majorana neutrino masses. The rotation induces charge asymmetries for the Higgs…
We demonstrate that $CP-$violation in the Majorana mass matrices of the heavy neutrinos can generate a $CP-$asymmetric universe. The subsequent decay of the Majorana particles generates a lepton number asymmetry. During the electroweak…
The inverse seesaw (ISS) model provides an attractive framework that can naturally explain the smallness of neutrino masses while accommodating some sterile neutrinos potentially accessible at present or future experiments. However, in…
Recently a Born-Infeld action for dark energy and dark matter that uses additional affine connections was proposed. At background level, it was shown that the new proposal can mimic the standard cosmological evolution. In Bianchi…
The baryon asymmetry of the Universe should have been produced after the inflation era. We consider the possibility that the asymmetry is generated by the flavor oscillations in the reheating process after inflation, so that the baryon…
Big-bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) anisotropy measurements give independent, accurate measurements of the baryon density and can test the framework of the standard cosmology. Early CMB data are consistent…
A large primordial lepton asymmetry can lead to successful baryogenesis by preventing the restoration of electroweak symmetry at high temperatures, thereby suppressing the sphaleron rate. This asymmetry can also lead to a first-order cosmic…
We propose a novel scenario to explain the matter-antimatter asymmetry by twofold leptogenesis, wherein heavy Majorana neutrinos exhibit temperature-dependent masses and engage in $CP$-violating decays. This scenario envisages two distinct…