Testing Horndeski gravity as dark matter with $\texttt{hi_class}$
Abstract
We consider a model of dark matter fluid based on a sector of Horndeski gravity. The model is very successful, at the background level, in reproducing the evolution of the Universe from early times to today. However, at the perturbative level the model fails. To show this, we use the code \texttt{hi_class} and we compute the matter power spectrum and the cosmic microwave background spectrum. Our results confirm, in a new and independent way, that this sector of Horndeski gravity is not viable, in agreement with the recent constraints coming from the measurement of the speed of gravitational waves obtained from the observation of the neutron star merger event GW170817.
Keywords
Cite
@article{arxiv.1807.01995,
title = {Testing Horndeski gravity as dark matter with $\texttt{hi_class}$},
author = {Alessandro Casalino and Massimiliano Rinaldi},
journal= {arXiv preprint arXiv:1807.01995},
year = {2019}
}
Comments
23 pages, 18 figures. References added, minor corrections, version accepted for publication in Physics of The Dark Universe