Related papers: Reheating Effects on Charged Lepton Yukawa Equilib…
Leptogenesis, i.e. the creation of a lepton asymmetry in the early Universe, may occur through the decay of heavy singlet (right-handed) neutrinos. If we require it not to be erased by physics beyond the Standard Model at the TeV energy…
We study if leptogenesis works successfully together with the neutrino mass anarchy hypothesis. We find that the predicted neutrino mass spectrum is sensitive to the reheating temperature or the inflaton mass, while the distributions of the…
Charged lepton flavour violation is reappraised in the context of supersymmetric see-saw mechanism. It is pointed out that a non-trivial flavour structure of right-handed neutrinos, whose effect has been thus far less studied, can give rise…
We discuss a D-term inflation scenario where a right-handed sneutrino can be an inflaton field leading to a viable inflation and leptogenesis, with a minimal form of K\"ahler potential. The decay of an inflaton sneutrino can non-thermally…
In this thesis, we study the role of flavours in leptogenesis. In a first time, we review the so-called one flavour picture, where only the lightest right-handed neutrino is taken into account, and where lepton flavours are neglected. After…
Low-scale leptogenesis is most efficient in the limit of an extreme mass degeneracy of right-handed neutrino flavours. Two variants of this situation are of particular interest: large neutrino Yukawa couplings, which boost the prospects of…
Models of leptogenesis are constrained by the low reheat temperature at the end of reheating associated with the gravitino bound. However a detailed view of reheating, in which the maximum temperature during reheating, $\Tmax$, can be…
In the early Universe above the weak scale, both baryon $B$ and lepton $L$ numbers are violated by nonperturabive effects in the Standard Model while $B-L$ remains conserved. Introducing new physics which violates perturbatively $L$ and/or…
We discuss the reheating temperature in the instant preheating scenario. In this scenario, at the last stage of inflation, the inflaton field first decays into another scalar field with an enormous number density via the instant preheating…
Any viable inflationary model must account for reheating of the universe prior to the onset of primordial nucleosynthesis. In this work, we study the reheating mechanism for an inflaton field with a quartic minimum, assuming that the main…
The rates for lepton number washout in extensions of the Standard Model containing right-handed neutrinos are key ingredients in scenarios for baryogenesis through leptogenesis. We relate these rates to real-time correlation functions at…
Flavor effects in leptogenesis reduce the region of the see-saw parameter space where the final predictions do not depend on the initial conditions, the strong wash-out regime. In this case we show that the lowest bounds holding on the…
In sneutrino hybrid inflation the superpartner of one of the right-handed neutrinos involved in the seesaw mechanism plays the role of the inflaton field. It obtains its large mass after the "waterfall" phase transition which ends hybrid…
An epoch of Higgs relaxation may occur in the early universe during or immediately following postinflationary reheating. It has recently been pointed out that leptogenesis may occur in minimal extensions of the Standard Model during this…
This thesis is devoted to some forefront issues in the field of leptogenesis. After reviewing the simplest picture where flavor effects are neglected and only the lightest right-handed neutrino contributes to the generation of 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…
Using the Closed-Time-Path approach, we perform a systematic leading order calculation of the relaxation rate of flavour correlations of left-handed Standard Model leptons. This quantity is of pivotal relevance for flavoured Leptogenesis in…
We discuss how a post inflationary reheating phase characterized by a nonstandard multiple scalar field cosmology can change the thermal history of the universe, affecting minimal high scale leptogenesis. In particular, we explore a class…
The importance of Yukawa contributions to the renormalization of the spectrum in non-minimal supersymmetric models is illustrated in the cases of explicit lepton number violation (leading to the possibility of singly produced sneutrinos at…
We propose a novel leptogenesis scenario at the reheating era. Our setup is minimal in the sense that, in addition to the standard model Lagrangian, we only consider an inflaton and higher dimensional operators. The lepton number asymmetry…