Related papers: Neutral-meson oscillations with torsion
We extend the treatment of quantum cosmology to a manifold with torsion. We adopt a model of Einstein-Cartan-Sciama-Kibble compatible with the cosmological principle. The universe wavefunction will be subject to a $\mathcal{PT}$-symmetric…
The present monograph is devoted to the theory of gravitation derived consequently as joint nonlinear realization of conformal and affine symmetries by means of Cartan differential forms. In the framework of the joint nonlinear realization…
Propagation of fermions in curved space-time generates gravitational interaction due to coupling of its spin with space-time curvature connection. This gravitational interaction, which is an axial-four-vector multiplied by a four…
The dynamics of a massive, relativistic spinning particle could be described either by the Dirac equation or by the Kerr solution of Einstein equations. However, one does not know a priori as to which of the two systems of equations should…
The dynamics of fermions on curved spacetime requires a spin connection, which contains a part called contorsion, an auxiliary field without dynamics but fully expressible in terms of the axial current density of fermions. Its effect is the…
We consider the generation and evolution of magnetic field in a primordial plasma at temperature T < 1 MeV in presence of asymmetric neutrino background i.e. the number densities of right- handed and left-handed neutrinos are not same.…
The observed baryon asymmetry of the Universe is suitably created in thermal leptogenesis through the out-of-equilibrium decay of $N_1$, the lightest of the three heavy singlet neutral fermions which anchor the seesaw mechanism to obtain…
The paper proposes an alternative scenario for the emergence of baryon asymmetry in the Universe. This scenario is realized in the lattice gravity model associated with the Dirac field as follows. At ultra-high temperatures of the Grand…
We show that an inhomogeneous cosmological lepton number may have produced turbulence in the primordial plasma when neutrinos entered (almost) free-streaming regime. This effect may be responsible for the origin of cosmic magnetic fields…
The inclusion of Dirac fermions in Einstein-Cartan gravity leads to a four-fermion interaction mediated by non-propagating torsion, which can allow for the formation of a Bardeen-Cooper-Schrieffer condensate. By considering a simplified…
We study nonthermal production of baryon and dark matter. If we extend the MSSM by introducing some singlet chiral superfields so as to enlarge the conserved global symmetry, the abundance of the baryon and the dark matter in the universe…
We review observational evidence for a matter-antimatter asymmetry in the early universe, which leads to the remnant matter density we observe today. We also discuss observational bounds on the presence of antimatter in the present day…
We show that Loop Quantum Gravity provides new mechanisms through which observed matter-antimatter asymmetry in the Universe can naturally arise at temperatures less than GUT scale. This is enabled through the introduction of a new length…
The minimal coupling of massless fermions to gravity does not allow for their gravitational production solely based on the expansion of the Universe. We argue that this changes in presence of realistic and potentially detectable stochastic…
We investigate the motion of a spinning test particle in a spatially-flat FRW-type space-time in the framework of the Einstein-Cartan theory. The space-time has a torsion arising from a spinning fluid filling the space-time. We show that…
The spin-torsion theory is a gauge theory approach to gravity that expands upon Einstein's general relativity (GR) by incorporating the spin of microparticles. In this study, we further develop the spin-torsion theory to examine spherically…
The present matter content of our universe may be governed by a $U(1)_{B-L}$ symmetry -- the simplest gauge completion of the seesaw mechanism which produces small neutrino masses. The matter parity results as a residual gauge symmetry,…
f(R)-theories of gravity are reviewed in the framework of the matter-antimatter asymmetry in the Universe. The asymmetry is generated by the gravitational coupling of heavy (Majorana) neutrinos with the Ricci scalar curvature. In order that…
We address the implementation of the cosmological principle, that is, the assumption of homogeneity and isotropy in the spatial distribution of matter in the Universe, within the context of Einstein-Cartan theory including minimal couplings…
Thermal leptogenesis explains the observed matter-antimatter asymmetry of the universe in terms of neutrino masses, consistent with neutrino oscillation experiments. We present a full quantum mechanical calculation of the generated lepton…