Sharov P. Matter density distribution and values of certain cosmological parameters on the base of peculiar velocities of flat galaxies

The thesis is devoted to reconstruction of matter density distribution, including dark matter, on scales up to 75 h^(-1) Mpc and estimations of cosmological parameters Omega_m and sigma_8 on the base of data on peculiar velocities of RFGC catalogue galaxies. A three-dimensional density field was obtained with the help of the POTENT method. Basic known peculiarities of the large-scale structure manifest themselves in the resulting distribution. The result also agrees well with alternative estimations of dark matter distribution. Excess masses estimations were made for basic attractors. Estimations of cosmological parameters Omega_m and sigma_8 were performed by using data about peculiar velocities of RFGC galaxies. Narrowness of 1-sigma area implies strong correlation between Omega_m and sigma_8 values. The results obtained agree well with numerous independent estimates. Comparison of radial velocity fields of collective motion of RFGC and Mark III galaxies was held. Acceptable likeness of their both large-scale and small-scale motions is demonstrated.