13 research outputs found
-Inflation and CMBR Anisotropy
We argue that a -inflation model can ensure large relative
contribution of cosmic gravity waves into the at COBE scale
preserving at the same time a near scale-invariant spectrum of cosmological
density perturbations favored by observational data (). High
efficiency of these models to meet observational tests is discussed.Comment: 5pages, to appear in "Cosmology and Particle Physics", eds
J.Garcia-Bellido, R.Durrer, and M.Shaposhniko
Absence of a Periodic Component in Quasar z-Distribution
Since the discovery of quasars in papers often appeared and appear the
assertions that the redshift quasar distribution includes a periodic component
with the period or 0.11. A statement of such kind, if it is
correct, may manifest the existence of a far order in quasar distribution in
cosmological time, that might lead to a fundamental revision all the
cosmological paradigm. In the present time there is a unique opportunity to
check this statement with a high precision, using the rich statictics of 2dF
and SDSS catalogues (about 85000 quasars). Our analysis indicates that the
periodic component in distribution of quasar redshifts is absent at high
confidence level
A solution to the problems of cusps and rotation curves in dark matter halos in the cosmological standard model
We discuss various aspects of the inner structure formation in virialized
dark matter (DM) halos that form as primordial density inhomogeneities evolve
in the cosmological standard model. The main focus is on the study of central
cusps/cores and of the profiles of DM halo rotation curves, problems that
reveal disagreements among the theory, numerical simulations, and observations.
A method that was developed by the authors to describe equilibrium DM systems
is presented, which allows investigating these complex nonlinear structures
analytically and relating density distribution profiles within a halo both to
the parameters of the initial small-scale inhomogeneity field and to the
nonlinear relaxation characteristics of gravitationally compressed matter. It
is shown that cosmological random motions of matter `heat up' the DM particles
in collapsing halos, suppressing cusp-like density profiles within developing
halos, facilitating the formation of DM cores in galaxies, and providing an
explanation for the difference between observed and simulated galactic rotation
curves. The analytic conclusions obtained within this approach can be confirmed
by the N-body model simulation once improved spatial resolution is achieved for
central halo regions.Comment: 44 pages, 16 figures, 1 tabl