Related papers: Comment on "Accelerating cosmological expansion fr…
It has been demonstrated that a modern stage of the Universe expansion may be described in accordance with the observations within the scope of the space-time conformal geometry. The clock synchronization procedure in SR has been…
In this work we explore a new cosmological solution for an universe filled with one dissipative fluid, described by a barotropic EoS $p = \omega \rho$, in the framework of the full Israel-Stewart theory. The form of the bulk viscosity has…
The coincidence problem of late cosmic acceleration constitutes a serious riddle with regard to our understanding of the evolution of the Universe. Here we argue that this problem may someday be solved -or better understood- by expressing…
It is shown that a present acceleration with a past deceleration is a possible solution of the Friedmann equation by considering the Universe as a mixture of a scalar with a matter field and by including a non-equilibrium pressure term in…
We investigate in detail the possibility that a single imperfect fluid with bulk viscosity can replace the need for separate dark matter and dark energy in cosmological models. With suitable choices of model parameters, we show that the…
Bianchi type V viscous fluid cosmological model for barotropic fluid distribution with varying cosmological term $\Lambda$ is investigated. We have examined a cosmological scenario proposing a variation law for Hubble parameter $H$ in the…
This study investigates the dynamics of a spatially homogeneous and anisotropic LRS Bianchi type-I universe with viscous fluid in the framework of $f(Q)$ symmetric teleparallel gravity. We assume a linear form for $f(Q)$ and introduce…
The kinematics and dynamic interpretation of the cosmological expansion is reviewed in a widely accessible manner with emphasis on the acceleration aspect. Virtually all the approaches that can in principle account for the accelerated…
Expansion dynamics of the Universe is one of the important subjects in modern cosmology. The dark energy equation of state determines this dynamics so that the Universe is in an accelerating phase. However, the dark matter can also affect…
A variety of physical phenomena can lead to viscous effects. In this talk we review several sources of shear and bulk viscosity with an emphasis on the bulk viscosity associated with chiral restoration. We show that in the limit of a second…
Recent cosmological and astrophysical observations point out that the Universe is in accelerating expansion and filled up with non-luminous matter. In order to explain the observed large scale structures and this accelerating behavior one…
It was argued by Brigante et.al that the lower bound on the ratio of the shear viscosity to the entropy density in strongly coupled plasma is translated into microcausality violation in the dual gravitational description. Since transport…
In string gas cosmology, the extra dimensions of the underlying theory are kept at a microscopic scale by a gas of strings. In the matter-dominated era, however, dust pressure can lead to oscillations of the extra dimensions and to…
It is shown that observed peculiarities of the Universe expansion are an inevitable consequence of the gravitational force properties following from gauge-invariant gravitation equations considered in detail in an author's paper in Annalen…
The viscous Cardassian cosmology is discussed, assuming that there is a bulk viscosity in the cosmic fluid. The dynamical analysis indicates that there exists a singular curve in the phase diagram of viscous Cardassian model. In the viscous…
The apparent superluminal growth in the size of a sufficiently large part of the universe can be ascribed to the special relativistic effect of time dilation.
The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting…
We present a discussion of the effects induced by the bulk viscosity on the very early Universe stability. The matter filling the cosmological (isotropic and homogeneous) background is described by a viscous fluid having an…
The averaged term of squared vorticity is attributed to accelerated expansion. Cosmological singularity has been a consequence of excessive symmetry of flow, such as "Hubble's law". More realistic one is suggested. Exact dynamic and…
The present day accelerated expansion of the universe is naturally addressed within the Brans-Dicke theory just by using holographic dark energy model with inverse of Hubble scale as IR cutoff. It is also concluded that if the universe…