Perspectives on Dark Energy

Abstract

The problem of dark energy is reviewed. The basic description of dark energy properties and parameterization is presented. Two alternative scenarios are examined, one invoking new gravitational phenomena, and another introducing a more fundamental revision of the standard cosmological model.

Dynamics of minimally coupled dark energy in spherical halos of dark matter

“…The results of integration of system of equation ( 28)- (34) with deceleration of infall of matter (35) which provides ∆ vir = 178 and virialized matter halo (36) are presented in the Figs. 4 for halos with k = 1.0 Mpc −1 and two values of c 2 s : 1.0 and 0.007. The initial amplitudes we set by putting…”

“…The progress of observational cosmology brings us more and more evidence of existence of dark energy, the nature of which is still unknown despite of significant efforts of researchers. On the other hand, the extensive theoretical modelling [1][2][3][4][5][6][7][8][9][10] of this component of our Universe leaves less and less hope that it is of the simplest type like cosmological constant. This encourages us to a deep analysis of the properties of different types of dark energy and its possible observational manifestations at different space-time scales.…”

Presence of Anisotropic Pressures in Lemaître–tolman–bondi Cosmological Models

“…In order to get rid of the above problems there has been put forward other kind of different models, where some exotic, unknown and uncluttered matter component, dubbed dark energy [5] (see also Refs. [6,7] for recent reviews) is considered. Among these possibilities are quintessence [8,9], k-essence [10][11][12], phantom field [13][14][15], holographic dark energy [16][17][18], etc.…”

The effect of curvature in thawing models

“…As this shows a result, that the pressure and the energy density of the universe should violate the strong energy condition, ρ φ + 3 p φ > 0, where ρ φ and p φ are energy density and pressure of some exotic, unknown and unclustered matter component, dubbed dark energy [4] (see also Refs. [5,6] for recent reviews). A direct consequence of this, is that the pressure must be negative.…”