title: Accelerating cosmological expansion from shear and bulk viscosity.
abstract: The dissipation of energy from local velocity perturbations in the cosmological fluid affects the time evolution of spatially averaged fluid dynamic fields and the cosmological solution of Einstein's field equations. We show how this backreaction effect depends on shear and bulk viscosity and other material properties of the dark sector, as well as the spectrum of perturbations. If sufficiently large, this effect could account for the acceleration of the cosmological expansion.
authors: Physics Department, Theory Unit, CERN, CH-1211 Genève 23, Switzerland.
authors: Stefan
authors: S
authors: Floerchinger
authors: Physics Department, Theory Unit, CERN, CH-1211 Genève 23, Switzerland.|Department of Physics, University of Athens, Zographou 157 84, Greece.
authors: Nikolaos
authors: N
authors: Tetradis
authors: Physics Department, Theory Unit, CERN, CH-1211 Genève 23, Switzerland.
authors: Urs Achim
authors: UA
authors: Wiedemann