Viscous Dark Cosmology with Account of Quantum Effects

TL;DR

This paper explores how quantum effects and bulk viscosity influence the nature and properties of future singularities in viscous dark energy cosmology, revealing modifications to singularity characteristics.

Contribution

It introduces the combined impact of quantum conformal anomaly and bulk viscosity on future cosmic singularities within dark energy models.

Findings

Quantum effects modify the singularity structure.

Bulk viscosity reduces the singularity time t_s.

The singularity's exponent remains unchanged.

Abstract

The analytic properties of the energy density rho(t) of the cosmic fluid, and the Hubble parameter H(t), are investigated near to the future singularity t=t_s assuming different forms for the equation of state. First, it is shown that the inclusion of quantum effects coming from the conformal anomaly modifies the singularity. Thereafter, we consider the effect coming from a bulk viscosity in the fluid. The viscosity tends to reduce the magnitude of t_s, but does not alter the singularity itself (the exponent). Main emphasis is laid on the simple case when the equation of state is p=w*rho, with w a constant.