Related papers: The Light Radion Window
Although observations made with the CoGeNT and CDMS experiments have been interpreted as possible signals of low-mass (~7-10 GeV) dark matter particles, constraints from the XENON100 collaboration appear to be incompatible with this…
The Minimal Supersymmetric Standard Model opens the possibility of electroweak baryogenesis provided that the light scalar top quark (stop) is lighter than the top quark. In addition, the lightest neutralino is an ideal candidate to explain…
Dark matter particles with masses in the sub-GeV range have escaped severe constraints from direct detection experiments such as LUX, PANDAX-II and XENON100 as the corresponding recoil energies are, largely, lower than the detector…
A new U(1) gauge symmetry is the simplest extension of the Standard Model and has various theoretical and phenomenological motivations. In this paper, we study the cosmological constraint on the MeV scale dark photon. After the neutrino…
Within the framework of the Standard Model of particle physics and standard cosmology, observations of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO) set stringent bounds on the sum of the masses of neutrinos.…
We examine the late-time (nucleosynthesis and later) cosmological implications of brane-world scenarios having large (millimeter sized) extra dimensions. In particular, recent proposals for understanding why the extra dimensions are so…
We consider the prospects for the indirect detection of low mass dark matter which couples dominantly to quarks. If the center of mass energy is below about 280 MeV, the kinematically allowed final states will be dominated by photons and…
Existing and planned observatories for cosmic neutrinos open up a huge window in energy from 10^7 to 10^17 GeV. Here, we discuss in particular the possibilities to use extremely energetic cosmic neutrinos as a diagnostic of astrophysical…
We explore in detail a dilatonic scalar-tensor theory of gravity inspired by large extra dimensions, where a radion field from compact extra dimensions gives rise to quintessence in our 4-dimensional world. We show that the model can give…
We consider the consequences of a neutral dark-matter particle with a nonzero electric and/or magnetic dipole moment. Theoretical constraints, as well as constraints from direct searches, precision tests of the standard model, the cosmic…
The presence of light (m_a ~ 10^-6 ev) scalar fields in the early universe can modify the cosmology of neutrinos considerably by allowing their masses to vary on cosmological times. In this paper, we consider the effect of Planck-suppressed…
Cosmology at present provides the nominally strongest constraint on the masses of standard model neutrinos. However, this constraint extremely dependent on the nature of the dark energy component of the Universe. When the dark energy…
The observation of cosmic sub-PeV gamma-rays from the Crab Nebula opens up the possibility of testing cosmic ray photon transparency at the multi-hundred TeV scale. Assuming no deviation from a source gamma-ray emission due to accelerated…
Recent results from direct detection experiments (Dama, CoGeNT), though subject to debate, seem to point toward a low mass (few GeV) dark matter (DM) particle. However, low mass DM candidates are not easily achieved in the MSSM nor NMSSM.…
With the advent of precision data, cosmology has become an extremely powerful tool for probing particle physics. The prime example of this is the cosmological bound on light neutrino masses. Here I review the current status of cosmological…
The power of a relativistic jet depends on the number of leptons and protons carried by the jet itself. We have reasons to believe that powerful gamma-ray flat spectrum radio sources emit most of their radiation where radiative cooling is…
We consider Randall-Sundrum two-brane cosmological model in the low energy gradient expansion approximation by Kanno and Soda. It is a scalar-tensor theory with a specific coupling function. We find a first integral of equations for the…
Interpretation of the energy spectrum and arrival distribution of cosmic rays is complicated by lack of knowledge of the nature of the primaries. We review claims for the mass composition above 1017 eV where it can be determined only…
We study the confinement/deconfinement phase transition of the radion field in a warped model with a polynomial bulk potential. The backreaction of the radion on the metric is taken into account by using the superpotential formalism, while…
For the 2-brane Randall-Sundrum model, we calculate the bulk geometry for strong gravity, in the low matter density regime, for slowly varying matter sources. This is relevant for astrophysical or cosmological applications. The warped…