相关论文: The Case for Dark Radiation

We investigate the dark energy phenomenology in an extended parameter space where we allow the curvature density of our universe as a free-to-vary parameter. The inclusion of the curvature density parameter is motivated from the recently…

Although the MiniBooNE experiment has severely restricted the possible existence of light sterile neutrinos, a few anomalies persist in oscillation data, and the possibility of extra light species contributing as a subdominant hot (or warm)…

The main goal of this work is to pursue an investigation of cosmic string configurations focusing on possible consequences of the Lorentz-symmetry breaking by a background vector. We analyze the possibility of cosmic strings as a viable…

This is a summary of a series of lectures on the current experimental and theoretical status of our understanding of origin and nature of cosmic radiation. Specific focus is put on ultra-high energy cosmic radiation above ~10^17 eV,…

A degenerate fermionic vacuum population is suggested. Based on the abundance of the dark energy density in the Universe the vacuum particle mass and number density are estimated. The obtained mass is in reasonable agreement with…

New precision Cosmic Microwave Background Radiation (CMBR) anisotropy data are beginning to constrain physics beyond the standard model, for example in the form of additional light particle species. These constraints are complementary to…

Cosmological first order phase transitions are typically associated with physics beyond the Standard Model, and thus of great theoretical and observational interest. Models of phase transitions where the energy is mostly converted to dark…

According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders…

According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu…

We investigate how the dark energy properties change the cosmological limits on sterile neutrino parameters by using recent cosmological observations. We consider the simplest dynamical dark energy models, the $w$CDM model and the…

Discoveries in the last few years have revolutionized our knowledge of the universe and our ideas of its ultimate fate. Measurements of the expansion of the universe show that it is not slowing down under normal gravity but accelerating due…

We apply phase-space density considerations to obtain lower bounds on the mass of sterile neutrino as dark matter candidate. The bounds are different for non-resonant production, resonant production in the presence of lepton asymmetry and…

Recent analyses of the diffuse TeV-PeV neutrino flux highlight a tension between different Ice-Cube data samples that strongly suggests a two-component scenario rather than a single steep power-law flux. Such a tension is further…

We address the emerging discrepancy between the Big Bang Nucleosynthesis data and standard cosmology, which asks for a bit longer evolution time. If this effect is real, one possible implication (in a framework of brane cosmology model) is…

If a component of cosmological dark matter is made up of massive particles - such as sterile neutrinos - that decay with cosmological lifetime to emit photons, the reionization history of the universe would be affected, and cosmic microwave…

We compute the cosmological background radiation of gamma rays and neutrinos due to neutralino annihilation in evolving dark matter halos, assuming the observed dark matter is comprised of thermally excited neutralinos in the MSSM. The…

The detection of excess radio background detected by ARCADE 2 suggests the presence of new physics as there exists no clear astrophysical solution. We find that the radiative decay of a relic neutrino into a sterile neutrino, assumed to be…

This thesis investigates the impact of dark matter on neutron star properties, focusing on mass, radius, and tidal deformability. Using two-fluid and single-fluid models, dark matter is incorporated into the equation of state (EOS) via a…

Dark radiation (DR) appears as a new physics candidate in various scenarios beyond the Standard Model. While it is often assumed that perturbations in DR are adiabatic, they can easily have an isocurvature component if more than one field…

The term dark radiation is used both to describe a noninteracting neutrino species and as a correction to the Friedmann Equation in the simplest five-dimensional RS-II brane-world cosmology. In this paper we consider the constraints on both…