13 research outputs found

    Λ\Lambda-Inflation and CMBR Anisotropy

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    We argue that a Λ\Lambda-inflation model can ensure large relative contribution of cosmic gravity waves into the ΔT/T\Delta T/T at COBE scale preserving at the same time a near scale-invariant spectrum of cosmological density perturbations favored by observational data (nS1n_S\simeq 1). 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

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    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 Δz=0.063\Delta z = 0.063 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

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    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

    Generation of cosmological flows in general relativity

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