Related papers: TeV scale gravity, mirror universe, and ... dinosa…
The introduction of extra space dimensions in the theory could be an elegant way tovsolve the hierarchy problem. There could even be one energy scale at which all interactions could unify. The limits coming from our knowledge of the…
We extend the Type I and Type III seesaw mechanisms to generate neutrino masses within the left-right symmetric theories where parity is spontaneously broken. We construct a next to minimal left-right symmetric model where neutrino masses…
I introduce the consequences of neutrino mass and mixing in the dense environments of the early Universe and in astrophysical environments. Thermal and matter effects are reviewed in the context of a two-neutrino formalism, with methods of…
Scalar-tensor theories of gravity are natural phenomenological alternatives to General Relativity, where the gravitational interaction is mediated by a scalar degree of freedom, besides the usual tensor gravitons. In regions of the…
Among three typical energy scales, a neutrino mass scale ($m_\nu\sim$ 0.1 eV), a GUT scale ($M_{GUT}\sim 10^{16}$ GeV), and a TeV-scale ($M_{NP}\sim 1$ TeV), there is a fascinating relation of $M_{NP}\simeq \sqrt{m_\nu\cdot M_{GUT}}$. The…
Arkani-Hamed, Dimopoulos, and Dvali have proposed that the fundamental gravitational scale is close to 1 TeV, and that the observed weakness of gravity at long distances is explained by the presence of large extra compact dimensions. If…
Recently there has been a lot of interest in models in which gravity becomes strong at the TeV scale. The observed weakness of gravitational interactions is then explained by the existence of extra compact dimensions of space, which are…
We address the question of dark matter in the context of gauge mediated supersymmetry breaking models. In contrast with mSUGRA scenarios, the messenger of the susy breaking to the visible sector can play an important role allowing a relic…
We propose a new scenario of incorporating neutrino masses in models of TeV scale gravity and large extra dimensions, which can explain the dark energy problem through formation of neutrino condensates. The smallness of the neutrino masses…
We suggest that recent neutrino puzzles that are the solar and atmospheric neutrino deficits as well as the possible neutrino oscillations reported by the LSND experiment and the possibility of massive neutrinos providing the hot component…
We explore the dynamics and evolution of the Universe at early and late times, focusing on both dark energy and extended gravity models and their astrophysical and cosmological consequences. Modified theories of gravity not only provide an…
We explore a simple solution to the cosmological challenges of the original Mirror Twin Higgs (MTH) model that leads to interesting implications for experiment. We consider theories in which both the standard model and mirror neutrinos…
The roles of massive neutrinos in cosmology -- in leptogenesis and in the evolution of mass density fluctuations -- are reviewed. Emphasis is given to the limit on neutrino mass from these considerations.
A TeV-scale scenario is constructed in an attempt to understand the relationship between quark and lepton masses. This scenario combines a model of early (TeV) unification of quarks and leptons with the physics of large extra dimensions. It…
We begin with a brief overview of highest-energy cosmic ray data, and the experiments which will perform neutrino astronomy. We then discuss two particle physics aspects of neutrinos. They are possible long-lifetime decay of the neutrino,…
I report on some scenarios where the gravitino is the dark matter and the supersymmetry breaking mediated by a gauge sector.
One of the most well-founded candidates for dark matter remains a split-SUSY model with a Higgsino-like or Wino-like lightest superpartner and the grander SUSY model providing answers for the hierarchy problem and GUT scale unification.The…
A desirable feature of models with large extra dimensions and a TeV range string scale is the possibility to understand an ultralight sterile neutrino needed for a simultaneous understanding of solar, atmospheric and LSND results as a…
We consider scalar-tensor theories of gravity in an accelerating universe. The equations for the background evolution and the perturbations are given in full generality for any parametrization of the Lagrangian, and we stress that apparent…
We review various TeV scale models for neutrino masses utilizing different types of seesaw mechanisms, higher dimensional operators, expanded gauge symmetries, or low scale extra dimensions. In addition, we discuss the implications of these…