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arXiv · 2108.11526

Gravitational Wave Distances in Horndeski Cosmology

Eric V. Linder
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Abstract

Gravitational wave propagation encounters a spacetime friction from a running Planck mass in modified gravity, causing the luminosity distance to deviate from that in general relativity (or given by the photon luminosity distance to the source), thus making it a valuable cosmological probe. We present the exact expression for the cosmological distance deviation in Horndeski gravity including theories that have a $G_5$ term yet propagate at the speed of light. An especially simple result ensues for coupled Gauss-Bonnet gravity, which we use to show it does not give a viable cosmology. We also generalize such coupling, and review the important connection of gravitational wave cosmological distance deviations to growth of cosmic structure measured by redshift space distortions.

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Eric V. Linder. 2021-08-26. Gravitational Wave Distances in Horndeski Cosmology. https://arxiv.org/abs/2108.11526

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