Gravitational wave luminosity distance in viscous cosmological models. Issue 8 (1st August 2022)

• Record Type: Journal Article
• Authors: Fanizza, Giuseppe; Pavone, Eliseo; Tedesco, Luigi
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2022:Issue 8(2022)
• Publication Date: 2022-08-01
• Subjects: gravitational waves / theory -- Gravitational waves in GR and beyond: theory -- Cosmological perturbation theory in GR and beyond; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2022/08/064
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: We study the so-called Gravitational Wave luminosity distance-redshift relation d L GW ( z ) during cosmological eras driven by non-perfect fluids. In particular, we show that the presence of a shear viscosity in the energy momentum tensor turns out to be the most relevant effect. Within this scenario, a constant shear viscosity imprints the gravitational wave propagation through a friction term δ ( z ) with a uniquely given redshift dependence. This peculiar evolution predicts a specific shape for the ratio d L GW / d L EM which tends to a constant value when the sources are at z ≳ 1, whereas scales linearly with the shear viscosity at lower redshifts, regardless of the value of Ω m 0 . According to our final discussion, the predicted redshift dependence δ ( z ) provided by a shear viscosity could be tested by upcoming surveys of multi-messenger sources against analogous scenarios provided by some widely studied theories of modified gravity.