İTÜ Fizik Mühendisliği Bölümü Semineri


27.10.2017 14:30 - 27.10.2017 15:30


Ayazağa Kampüsü, Ayazağa Kampüsü

Etkinlik Kategorisi


Abstract We study the Universe filled with CDM in the form of discrete inhomogeneities (e.g., galaxies) and DE in the form of arbitrary continuous perfect fluids. The background space-time geometry is defined by the FLRW metric. In the weak gravitational field limit, we develop the first-order scalar cosmological perturbation theory. Our approach works at all cosmological scales and incorporates linear and nonlinear effects with respect to energy density fluctuations. The gravitational potentials produced by matter fluctuations are characterized by a finite time-dependent Yukawa interaction range being the same for each individual contribution and which is of the order of 3700 Mpc at the present time. Therefore, the gravitational potential of the n-th fluctuation is exponentially suppressed at such scales. This suppression is called the cosmological screening. The derived equations can form the theoretical basis for numerical simulations of a structure formation in the Universe for a wide class of cosmological models.