Black holes in the turbulence phase of viscous rip cosmology

Abstract

We study the phantom fluid in the late universe, thus assuming the equation of state parameter [Formula: see text] to be less than [Formula: see text]. The fluid is assumed to consist of two components, one laminar component [Formula: see text] and one turbulent component [Formula: see text], the latter set proportional to [Formula: see text] as well as to the Hubble parameter, [Formula: see text] with [Formula: see text] a positive constant associated with the turbulence. The effective energy density is taken to be [Formula: see text], and the corresponding effective pressure is [Formula: see text], with [Formula: see text] constant. These basic assumptions lead to a Big Rip universe; the physical quantities diverging during a finite rip time [Formula: see text]. We then consider the mass accretion of a black hole in such a universe. The most natural assumption of setting the rate [Formula: see text] proportional to [Formula: see text] times the sum [Formula: see text] leads to a negative mass accretion, where [Formula: see text] goes to zero linearly in [Formula: see text] near the singularity. The Hubble parameter diverges as [Formula: see text], whereas [Formula: see text] and [Formula: see text] diverge as [Formula: see text]. We also discuss other options and include, for the sake of comparison, some essential properties of mass accretion in the early (inflationary) universe.