Related papers: Anthropic Bound on Dark Radiation and its Implicat…
New measurements of the cosmic microwave background (CMB) by the Planck mission have greatly increased our knowledge about the Universe. Dark radiation, a weakly interacting component of radiation, is one of the important ingredients in our…
Stellar objects (including our Sun, other stars of main sequence, white dwarfs, neutron stars etc.) contain strongly degenerate low energy sea of neutrinos (in neutron stars) or antineutrinos. The presence of this sea leads due to Pauli…
Experimental developments in neutrino telescopes are drastically improving their ability to constrain the annihilation cross-section of dark matter. In this paper, we employ an angular power spectrum analysis method to probe the galactic…
The existence of multiple regions of space beyond the observable Universe (within the so-called "multiverse") where the vacuum energy density takes different values, has been postulated as an explanation for the low non-zero value observed…
We have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope in the Milky Way Halo region searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal,…
We used a consistent and robust solar model to obtain upper limits placed by neutrino telescopes, such as Ice- Cube and Super-Kamiokande, on the Dark Matter-nucleon scattering cross-section, for a general model of Dark Matter with a…
We present a unified dark fluid model to describe the possible evolutionary behavior of $\Delta N_\mathrm{eff}$ in dark radiation. This model can be viewed as an interacting model for the dark sectors, in which dark matter interacts with…
It is generally expected that adding light sterile species would increase the effective number of neutrinos, $N_{eff}$. In this paper we discuss a scenario that $N_{eff}$ can actually decrease due to the neutrino oscillation effect if…
The effects of astrophysical uncertainties on the exclusion limits at dark matter direct detection experiments are investigated for three scenarios: elastic, momentum dependent and inelastically scattering dark matter. We find that varying…
The search for extraterrestrial intelligence includes efforts to constrain populations of artificial broadcasts in other galaxies. Previous efforts use individualist methods, searching for single broadcasts with high signal-to-noise ratio.…
We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an…
We discuss the possibility to find an upper bound on the seesaw scale using the cosmological bound on the cold dark matter relic density. We investigate a simple relation between the origin of neutrino masses and the properties of a dark…
We entertain the exotic possibility that dark matter (DM) decays or annihilations taking place in our galaxy may produce a flux of relativistic very weakly-coupled bosons, axions or dark photons. We show that there exist several upper…
Dark Matter in Earth intersecting orbits can scatter off the electrons and lose energy, and finally be gravitationally bound to Earth. Eventually they lose enough energy and accumulate at the core. It is assumed that DM annihilates/decays…
We present a complete analysis of the observational constraints and cosmological implications of our Bound Dark Energy (BDE) model aimed to explain the late-time cosmic acceleration of the universe. BDE is derived from particle physics and…
Dwarf galaxies represent a powerful probe of annihilating dark matter particle models, with gamma-ray data setting some of the best bounds available. A major issue in improving over existing constraints consists in the limited knowledge of…
We revisit cosmological neutrino mass bounds when a fraction of dark matter is allowed to decay to massless dark radiation. By compensating the late-time increase in the matter density induced by neutrinos becoming non-relativistic,…
We show that the cosmological constant at late time places a bound on the entropy of microwave background radiation deposited in the future event horizon of a given observer, $S\leq S_{\Lambda_0}^{3/4}$. This bound is independent of the…
We argue that the reflection of relic neutrinos from the surface of the Earth results in a significant local $\nu-\bar{\nu}$ asymmetry, far exceeding the expected primordial lepton asymmetry. The net fractional electron neutrino number…
In the past decade, gamma-ray observations and radio observations put strong constraints on the parameters of dark matter annihilation. In this article, we suggest another robust way to constrain the parameters of dark matter annihilation.…