[en] We discuss leptogenesis in a realistic supersymmetric model of inflation with a low reheat temperature 1endash10 GeV. The lepton asymmetry is generated by a decaying right-handed sneutrino, which is produced after inflation during preheating. The inflationary model is based on a simple variant of the next-to-minimal supersymmetric standard model (NMSSM) which solves the μ problem, called φNMSSM, where the additional singlet φ plays the role of the inflaton in hybrid (or inverted hybrid) type models. The model is invariant under an approximate Peccei-Quinn symmetry which also solves the strong CP problem, and leads to an invisible axion with interesting cosmological consequences. We show how the baryon number of the universe and the nature of cold dark matter are determined by the same parameters controlling the strong CP problem, the μ problem, and the neutrino masses and mixing angles

[en] We consider the problem of trying to understand the recently measured neutrino data simultaneously with understanding the hierarchical form of quark and charged-lepton Yukawa matrices. We summarize the data that a successful model of neutrino mass must predict, and then move on to attempting to do so in the context of spontaneously broken 'family' symmetries. We consider first an abelian U(1) family symmetry, which appears in the context of a type-I string model. Then we consider a model based on a non-abelian SU(3)_F , which is the maximal family group consistent with an SO(10) GUT. In this case, the symmetry is more constraining, and is examined in the context of SUSY field theory.

[en] In this talk we discuss the role of non-Abelian family symmetry in constructing realistic grand unified theories capable of providing an explanation of the quark and lepton masses and mixings

[en] I discuss the implications of neutrino oscillations for neutrino mass patterns and mass matrices, and for neutrinoless double beta decay. I then go on to discuss the implications for cosmological relic density and dark matter, the galaxy structure limits on neutrino mass, nucleosynthesis, supernovae, cosmic rays and gamma ray bursts

[en] This is a review article about neutrino mass models, particularly see-saw models involving three active neutrinos that are capable of describing both the atmospheric neutrino oscillation data and the large mixing angle (LMA) MSW solar solution, which is now uniquely specified by recent data. We briefly review the current experimental status, show how to parametrize and construct the neutrino mixing matrix, and present the leading order neutrino Majorana mass matrices. We then introduce the see-saw mechanism and discuss a natural application of it to current data using the sequential dominance mechanism, which we compare with an early proposal for obtaining LMAs. We show how both the Standard Model and the Minimal Supersymmetric Standard Model may be extended to incorporate the see-saw mechanism and show how the latter case leads to the expectation of lepton flavour violation. The see-saw mechanism motivates models with additional symmetries such as unification and family symmetry models, and we tabulate some possible models before focusing on two particular examples based on SO(10) grand unification and either U(1) or SU(3) family symmetry as specific examples. This review contains extensive appendices that include techniques for analytically diagonalizing different types of mass matrices involving two LMAs and one small mixing angle, to leading order in the small mixing angle

[en] We analyze the effects of charged lepton corrections and renormalization group (RG) running on the low energy predictions of theories which accurately predict tri-bimaximal neutrino mixing at the high energy scale. In particular we focus on grand unified theory (GUT) inspired seesaw models with accurate tri-bimaximal neutrino mixing at the GUT scale, in which the charged lepton corrections are Cabibbo-like and give rise to sum rules valid at the GUT scale. We study numerically the RG corrections to a variety of such neutrino mixing sum rules in order to assess their accuracy and reliability when comparing them to future low energy neutrino oscillation experiments. Our results indicate that the RG corrections to neutrino mixing sum rules are typically small (less than one degree), at least in the examples studied with hierarchical neutrinos.

[en] We review the mechanism of sequential right-handed neutrino dominance proposed in the framework of the type I see-saw mechanism to account for bi-large neutrino mixing and a neutrino mass hierarchy in a natural way. We discuss how sequential dominance (SD) may also be applied to the right-handed charged leptons, which alternatively allows for bi-large lepton mixing from the charged lepton sector. We review how such SD models may be upgraded to include type II see-saw contributions, resulting in a partially degenerate neutrino mass spectrum with the bi-large lepton mixing arising from SD. We also summarize the model-building applications and the phenomenological implications of SD

[en] In this talk we survey some of the recent promising developments in the search for the theory behind neutrino mass and mixing, and indeed all fermion masses and mixing. The talk is organized in terms of a neutrino mass models road map according to which the answers to experimental questions provide sign posts to guide us through the maze of theoretical models eventually towards a complete theory of flavour and unification.

[en] In this talk we discuss an E6 inspired supersymmetric (SUSY) model with an extra U(1)N gauge symmetry under which right-handed neutrinos have zero charge. In this exceptional supersymmetric standard model (E6SSM) the μ-term is generated dynamically after the electroweak symmetry breaking. We specify the particle content of the model and argue that the presence of a Z' and exotic particles predicted by E6SSM allows the lightest Higgs boson to be significantly heavier than in the MSSM and NMSSM. Other possible manifestations of E6SSM at the LHC are also discussed

[en] In this talk I give an overview of current approaches in neutrino theory and the key experimental questions which will enable progress to be made.