Related papers: Dark Matter and Cosmic Strings in Particle Models
It is possible that the strongest interactions between dark matter and the Standard Model occur via the neutrino sector. Unlike gamma rays and charged particles, neutrinos provide a unique avenue to probe for astrophysical sources of dark…
Recently, the CDMS experiment has reported the possible first direct-detection of dark matter. We update the direct-detection constraints for neutralino dark matter arising in a realistic string model constructed from intersecting D6-branes…
We discuss the possible dynamical role of extended cosmic defects on galactic scales, specifically focusing on the possibility that they may provide the dark matter suggested by the classical problem of galactic rotation curves. We…
A long-standing problem of theoretical physics is the exceptionally small value of the cosmological constant $\Lambda \sim 10^{-120}$ measured in natural Planckian units. Here we derive this tiny number from a toroidal string cosmology…
Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via…
We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and…
Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the…
The cosmological significance of the neutralino sector is studied for a class of models in which electroweak symmetry breaking is seeded by a gauge singlet. Extensive use is made of the renormalisation group equations to significantly…
We reconsider non-thermal production of WIMP dark matter in a systematic way and using a numerical code for accurate computations of dark matter relic densities. Candidates with large pair annihilation rates are favored, suggesting a…
We compute the linear power spectrum of cosmic string sedeed fluctuations in the context of neutrinos with a strong self-interaction and show that it is very similar to that obtained in the context of `normal' neutrinos. We compare our…
We propose an alternative scenario for the dark matter generation from an evolving cosmological constant which interacts with the dominant background in certain intermediate phase of the universe, and relaxes to the observed small value at…
We investigate the production of neutralino dark matter in a cosmological scenario featuring an early matter dominated era ending at a relatively low reheating temperature. In such scenarios different production mechanisms of weakly…
In usual particle models, sterile neutrinos can account for the dark matter of the Universe only if they have masses in the keV range and are warm dark matter. Stringent cosmological and astrophysical bounds, in particular imposed by X-ray…
We describe two new generation mechanisms for Dark Matter composed of sterile neutrinos with ${\cal O}(1)$ keV mass. The model contains a light scalar field which coherently oscillates in the early Universe and modulates the Majorana mass…
We study the possibility to describe dark matter in a model of the universe with two scale factors and a non-standard Poisson bracket structure characterized by the deformation parameter \kappa. The dark matter evolution is analyzed in the…
We investigate the observational constraints on an interacting vacuum energy scenario with two different neutrino schemes (with and without a sterile neutrino) using the most recent data from CMB temperature and polarization anisotropy,…
Dark energy, the main constituent in our expanding universe, responsible for its acceleration, is currently being observed with unprecedented precision through various experiments. While several cosmological models can fit this latest data,…
We present a comprehensive analysis of constraints on the sterile neutrino as a dark matter candidate. The minimal production scenario with a standard thermal history and negligible cosmological lepton number is in conflict with…
We study a simple model of thermal dark matter annihilating to standard model neutrinos via the neutrino portal. A (pseudo-)Dirac sterile neutrino serves as a mediator between the visible and the dark sectors, while an approximate lepton…
All presently known stellar-dynamical constraints on the size and mass of the supermassive compact dark object at the Galactic center are consistent with a ball of self-gravitating, nearly non-interacting, degenerate fermions with mass…