Related papers: Cosmological and Astrophysical Constraints on Tens…
Cosmology is at present one of the most powerful probes of neutrino properties. The advent of precision data from the cosmic microwave background and large scale structure has allowed for a very strong bound on the neutrino mass. Here, I…
In the framework of the standard, hot big bang cosmological model the dynamics of the early evolution of the universe is controlled by the energy density of relativistic particles, among which neutrinos play an important role. In…
There are well-known bounds on light neutrino masses from cosmological energy density arguments. These arguments assume the neutrinos to be non-degenerate. We show how these bounds are affected if the neutrinos are degenerate. In this case,…
Considering the observed anisotropy in cosmic microwave background radiation ($\Delta T/T \leq 10^{-4}$) an upper limit on the electric charge asymmetry over a cosmological scale is found which is several orders more stringent than those…
We consider the influence of non-equilibrium electronic neutrinos (and anti-neutrinos) on the neutron-to-proton ratio. These neutrinos would come from massive $\nu_\tau$ annihilations $\bar \nu_\tau \nu_\tau \rightarrow \bar \nu_e \nu_e$.…
We study the cosmological constraints on unparticle interactions and the temperature of the Universe for the case where unparticle states can be modelled as continuous mass particles with lifetime > 1s. By considering thermal background…
Cosmological constraints on the sum of neutrino masses and on the effective number of neutrino species in standard and non-standard scenarios are computed using the most recent available cosmological data. Our cosmological data sets include…
We ask if the conventional variable separation techniques in the studying of standard cosmology and the collapsing of extremely dense stars introduce Newton's absolute space-time concepts. If this is the case, then a completely relative…
Using several cosmological observations, i.e. the cosmic microwave background anisotropies (WMAP), the weak gravitational lensing (CFHTLS), the measurements of baryon acoustic oscillations (SDSS+WiggleZ), the most recent observational…
General relativistic calculations are made of neutrino-antineutrino annihilation into electron-positron pairs near the surface of a neutron star. It is found that the efficiency of this process is enhanced over the Newtonian values up to a…
Non-standard interactions (NSI) between neutrinos and electrons can significantly modify the decoupling of neutrinos from the plasma. These interactions have two effects on the overall picture: (i) they alter neutrino oscillations though…
We present cosmological perturbation theory in neutrinos probe interacting dark-energy models, and calculate cosmic microwave background anisotropies and matter power spectrum. In these models, the evolution of the mass of neutrinos is…
We study how present data probe standard and non-standard properties of neutrinos and the possible existence of new light particles, freely-streaming or interacting, among themselves or with neutrinos. Our results include: sum m_nu < 0.40…
We study a scenario that a hidden gaugino dark matter decays into the standard-model particles (and their supersymmetric partners) through a kinetic mixing with the gaugino of a U(1)B-L broken at a scale close to the grand unification…
We calculate the stellar energy loss due to neutrino-pair production in $e^+e^-$ annihilation in the context of a 331 model, a left-right symmetric model and a simplest little Higgs model in a way that can be used in supernova calculations.…
We combine the most recent observations of large-scale structure (2dF and SDSS galaxy surveys) and cosmic microwave anisotropies (WMAP and ACBAR) to put constraints on flat cosmological models where the number of massive neutrinos and of…
In this letter we propose a possible mechanism of left- and right-handed neutrino couplings to photons, which arises quite naturally in non-commutative gauge field theory. We estimate the predicted additional energy-loss in stars induced by…
The constraint on the ADD model of extra dimensions coming from photon annihilation into Kaluza-Klein graviton in supernova cores is revisited. In the two photon process for a conservative choice of the core parameters, we obtain the bound…
We calculate the rate of production of dark photons from electron-positron pair annihilation in hot and dense matter characteristic of supernova progenitors. Given the non-linear dependence of the emission rate on the dark photon mass and…
We investigate the impact of unparticle physics on the annihilation of relic neutrinos with the neutrinos identified as primary source of ultra high energy (UHE) cosmic ray events, producing a cascade of photons and charged particles. We…