Related papers: Concordance of X-Ray Cluster Data With BBN In Mixe…
Recent results have suggested that the density of baryons in the Universe, OmegaB, is much more uncertain than previously thought, and may be significantly higher. We demonstrate that a higher OmegaB increases the viability of…
We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a Cold + Hot Dark Matter (CHDM) model. We have performed a hydrodynamic plus N-body simulation for the COBE-compatible CHDM…
We present results from the analysis of cosmic microwave background (CMB), large scale structure (galaxy redshift survey) and X-ray galaxy cluster (baryon fraction and X-ray luminosity function) data, assuming a geometrically flat…
Nucleosynthesis in the standard hot big bang cosmology offers a successful account of the production of the light nuclides during the early evolution of the Universe. Consistency among the predicted and observed abundances of D, $^3$He,…
Clusters of galaxies are thought to contain about ten times as much dark matter as baryonic matter. The dark component therefore dominates the gravitational potential of the cluster, and the baryons confined by this potential radiate X-rays…
We discuss the structure of clusters in a class of flat cosmological models with the fraction of mass \Omega_{CDM} ~0.8 in cold dark matter, and the rest in hot dark matter in the form of massive neutrinos. We consider such Cold+Hot Dark…
Direct observations of the supposedly universal primordial deuterium abundance imply a relatively large baryon density $\Omega_B= (0.019-0.030)h^{-2}$ (95% C.L.). On the other hand, concordance between the previously accepted $^4 He$ and…
We exmaine the distribution of hot gas in a standard CDM model of the universe using high resolution hydrodynamic simulations. Adopting standard parameters determined from COBE and light element nucleosynthesis, $\sigma_8=1.05$,…
Recent data on CBR anisotropies show a Doppler peak higher than expected in CDM cosmological models, if the spectral index $n=1$. However, CDM and LCDM models with n>1 can hardly be consistent with LSS data. Mixed models, instead, whose…
Gravitational lensing observations of massive X-ray clusters imply a steep characteristic density profile marked by a central concentration of dark matter. The observed mass fraction within a projected radius of 150 kpc is twice that found…
We calculate the large-angle cross-correlation between the cosmic-microwave-background (CMB) temperature and the x-ray-background (XRB) intensity expected in an open Universe with cold dark matter (CDM) and a nearly scale-invariant spectrum…
The recent Boomerang and MAXIMA data on the cosmic microwave background suggest a large value for the baryonic matter density of the universe, omega_b = 0.03. This density is larger than allowed by standard big bang nucleosynthesis theory…
We study the properties of X-ray galaxy clusters in four cold dark matter models with different baryon fraction $\Omega_{BM}$ ranging from 5 to 20 per cent. By using an original three-dimensional hydrodynamic code based on the piecewise…
The BBN predictions for the abundances of the light element isotopes is reviewed and compared with recent observational data. The single unknown parameter of standard BBN is the baryon-to-photon ratio, \eta, and can be determined by the…
We consider the Big Bang Nucleosynthesis (BBN) bounds on light dark matter whose cross section off nucleons is sufficiently large to enable acceleration by scattering off of cosmic rays in the local galaxy. Such accelerated DM could then…
We study the spherical, top-hat collapse model for a mixed dark matter model including cold dark matter (CDM) and massive neutrinos of mass scales ranging from m_nu= 0.05 to a few 0.1eV, the range of lower- and upper-bounds implied from the…
Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) have a long history together in the standard cosmology. The general concordance between the predicted and observed light element abundances provides a direct probe of…
The universal baryonic mass fraction (Omega_b/Omega_m) can be sensitively constrained using X-ray observations of galaxy clusters. In this paper, we compare the baryonic mass fraction inferred from measurements of the cosmic microwave…
Although very successful in explaining the observed conspiracy between the baryonic distribution and the gravitational field in spiral galaxies without resorting to dark matter (DM), the modified Newtonian dynamics (MOND) paradigm still…
It is known that the cosmological baryon density ($\Omega_{\rm{b}}$) and dark matter density ($\Omega_{\rm{dm}}$) have strikingly similar values. However, in most theories of the early Universe, each density is explained by separate…