Related papers: Thermal leptogenesis in brane world cosmology
We show that gravitational leptogenesis with dynamical $CPT$ breaking in an expanding universe can be reconciled with the exponential $f(R)$ gravity model, which introduces only one additional parameter $\beta$ compared to the standard…
Thermal leptogenesis and supergravity are attractive scenarios for physics beyond the standard model. However, it is well known that the super-weak interaction of the gravitino often leads to problems with primordial nucleosynthesis in the…
We present a general description of the problems encountered when attempting to build a simple model of leptogenesis and hence of baryogenesis at an energy scale as low as 1-10 TeV. We consider three possible lepton asymmetry enhancement…
We point out that there is no cosmological gravitino problem in a certain class of gauge-mediated supersymmetry-breaking (GMSB) models. The constant term in the superpotential naturally causes small mixings between the standard-model and…
One of the major challenges in particle physics and cosmology is understanding why there is an asymmetry between matter and antimatter in the Universe. One possible explanation for this phenomenon is thermal leptogenesis, which involves the…
We reanalyze the supersymmetric leptogenesis model by one of the authors (HM) and Yanagida based on \tilde{L} = H_u flat direction in detail. We point out that the appropriate amount of baryon asymmetry can be generated in this model with…
We study the simplest theories with exact spacetime parity that solve the strong CP problem and successfully generate the cosmological baryon asymmetry via decays of right-handed neutrinos. Lower bounds are derived for the masses of the…
We present a general analysis that reveals new aspects of the leptogenesis bounds on neutrino masses and on the reheat temperature of the Universe. After revisiting a known effect coming from an unbounded term in the total CP asymmetry, we…
We have studied extensively phenomenological implications in a specific model of brane inflation driven by background supergravity, via thermal history of the universe and leptogenesis pertaining to the particle physics phenomenology of the…
Interactions of heavy Majorana neutrinos in the thermal phase of the early universe may be the origin of the cosmological matter-antimatter asymmetry. This mechanism of baryogenesis implies stringent constraints on light and heavy Majorana…
During the process of thermal leptogenesis temperature decreases by about one order of magnitude while the baryon asymmetry is generated. We present an analytical description of this process so that the dependence on the neutrino mass…
We discuss leptogenesis in a model with heavy right-handed Majorana neutrinos propagating in a constant but otherwise generic CPT-violating axial time-like background (which could be motivated by string theory considerations). At…
Entropy bounds applied to a system of N species of light quantum fields in thermal equilibrium at temperature T are saturated in four dimensions at a maximal temperature T_max=M_Planck/N^1/2. We show that the correct setup for understanding…
We show that a phase transition may take place in the early Universe at a temperature $T_*$ via a Standard Model singlet scalar field which happens to couple to right handed neutrinos (RHN) resulting a temperature dependent mass for them…
Our present work explores the possibility of neutrino mass generation through {\em Type-I see-saw} mechanism and provides an explanation of the baryon asymmetry of the Universe via thermal leptogenesis in the framework of $Z_3$-symmetric…
We explore the cosmological dynamics of a supercooled first-order phase transition in the classically conformal $U(1)_{B-L}$ extension of the Standard Model, where radiative symmetry breaking simultaneously generates the right-handed…
Using the closed-time-path formalism we quantify gradient corrections to the kinetic equations for leptogenesis, that are neglected in the standard Boltzmann approach. In particular we show that an additional CP-violating source term…
Strictly adhering to the standard supersymmetric seesaw mechanism, we present a neutrino mass model which allows successful standard thermal leptogenesis compatible with gravitino cosmology. At least some of the neutrino Yukawa couplings…
Successful soft leptogenesis requires small B-terms for the right-handed sneutrinos and a large CP violating phase between the A- and B-terms. We show that this situation is realized naturally within the framework of gauge mediated…
In the framework of seesaw models with only two heavy Majorana neutrinos, nonzero leptonic asymmetries can be radiatively generated when exact heavy neutrino mass degeneracy ($M_1=M_2=M$) is imposed at a scale $\Lambda_D > M$. For a…