Related papers: Damped Lyman Alpha Systems vs. Cold + Hot Dark Mat…
The hierarchical cold dark matter (CDM) model for structure formation is a well defined and testable model. Direct detection is the best technique for confirming the model yet predictions for the energy and density distribution of particles…
We study the average Ly$\alpha$ emission associated with high-$z$ strong (log $N$(H I) $\ge$ 21) damped Ly$\alpha$ systems (DLAs). We report Ly$\alpha$ luminosities ($L_{\rm Ly\alpha}$) for the full as well as various sub-samples based on…
The abundance of dark matter satellites and subhalos, the existence of density cusps at the centers of dark matter halos, and problems producing realistic disk galaxies in simulations are issues that have raised concerns about the viability…
The $ee\gamma\gamma +\rlap/E_T$ event observed by the CDF at Fermilab is naturally explained by dynamically supersymmetry breaking models and suggests the presence of the light gravitino which can be a warm dark matter. We consider large…
We investigate the properties of damped Lyman-alpha systems (DLAS) in semi-analytic models, focusing on whether the models can reproduce the kinematic properties of low-ionization metal lines described by Prochaska & Wolfe (1997b, 1998). We…
The abundance of dark matter satellites and subhalos, the existence of density cusps at the centers of dark matter halos, and problems producing realistic disk galaxies in simulations are issues that have raised concerns about the viability…
We study the constraints that high-redshift structure formation in the universe places on warm dark matter (WDM) dominated cosmological models. We modify the extended Press-Schechter formalism to derive the halo mass function in WDM models.…
Annihilating dark matter (DM) models offer promising avenues for future DM detection, in particular via modification of astrophysical signals. However when modelling such potential signals at high redshift the emergence of both dark matter…
We have examined some basic properties of damped Ly$\alpha$ systems(DLAs) by semi-analytic model. We assume that DLA hosts are disk galaxies whose mass function is generated by Press-Schechter formulism at redshift 3. Star formation and…
We analyze the properties of dark matter halos in the cold-plus-warm dark matter cosmologies (CWDM). We study their dependence on the fraction and velocity dispersion of the warm particle, keeping the free-streaming scale fixed. To this end…
We perform a study of the nonlinear clustering of matter in the late-forming dark matter (LFDM) scenario in which dark matter results from the transition of a nonminimally coupled scalar field from radiation to collisionless matter. A…
The local power law relationship between the surface densities of neutral hydrogen gas and star formation rate (SFR) can be used to explore the SFR properties of damped Lyman alpha (DLA) systems at higher redshift. We find that while the…
We predict the observable properties of the galaxy population in popular hierarchical models of galaxy formation. We employ a detailed semianalytic procedure which incorporates the formation and merging of dark matter halos, the shock…
We use the moments of counts of neighbors as given by the Generalized Correlation Integrals, to study the clustering properties of Dark Matter Halos (DH) in Cold Dark Matter (CDM) and Cold+Hot Dark Matter (CHDM) models. We compare the…
Quasar absorption systems not only affect the way quasars are selected, but also serve as key probes of galaxies, providing insight into their chemical evolution and interstellar medium (ISM). Recently, a method based on Gaia astrometric…
We present zoom-in N-body + Hydrodynamic simulations of dwarf central galaxies formed in Warm Dark Matter (WDM) halos with masses at present-day of $2-4\times 10^{10}$ \msun. Two different cases are considered, the first one when halo…
Cold + Hot Dark Matter (CHDM) $\Omega=1$ cosmological models require a total neutrino mass $\sim 5$ eV. Because recent data support the $\nu_\mu \to \nu_\tau$ oscillation explanation of the cosmic ray $\nu_\mu$ deficit, which requires that…
Formation of sub-galactic halos is suppressed in warm dark matter (WDM) model due to thermal motion of WDM particles. This may provide a natural resolution to some puzzles in standard cold dark matter (CDM) theory such as the cusped density…
Weakly interacting cold dark matter (CDM) particles, which are otherwise extremely successful in explaining various cosmological observations, exhibit a number of problems on small scales. One possible way of solving these problems is to…
Cold Dark Matter (CDM) models struggle to match the observations at galactic scales. The tension can be reduced either by dramatic baryonic feedback effects or by modifying the particle physics of CDM. Here, we consider an ultra-light…