DETERMINING THE MASS OF THE UNIVERSE

[摘要] The average mass density of the Universe, parameterized by {Omega}, is the most sought after single number in cosmology. It determines whether the Universe is open, expanding forever ({Omega} < 1) or closed, eventually recollapsing ({Omega} > 1). Unfortunately, after a half century of research {Omega} is still uncertain by at least a factor of five. Most of the mass is in the form of dark matter, and the precise relationship between its distribution and the distribution of the observable galaxies is still not known. We have the developed tools that may significantly improve the measurements of the mass of the Universe. We have performed state-of-the-art numerical simulations that provide complete dynamical information about both galaxies and dark matter, and our work has shown that the usual treatment of galaxies as point masses is unjustified. Additionally, we have proposed a method to determine the cosmic mass density from redshift-space distortions induced by large-scale flows in the presence of nonlinear clustering.

[发布日期] 2000-11-01 [发布机构] Los Alamos National Laboratory

[关键词] Universe;Nonluminous Matter;Cosmology;Galaxies;Mass