Nonlinear power spectrum and forecasts for a generalized cubic covariant Galileon

Physical review. D/Physical review. D., vol. 110

Abstract

To fully exploit the data from next generation surveys, we need an accurate modeling of the matter power spectrum up to nonlinear scales. Therefore in this work we present the halo model reaction framework for the generalized cubic covariant Galileon (GCCG) model, a modified gravity model within the Horndeski class of theories which extends the cubic covariant Galileon (G3) by including power laws of the derivatives of the scalar field in the K-essence and cubic terms. We modify the publicly available software react for the GCCG in order to obtain an accurate prediction of the nonlinear power spectrum. In the limit of the G3 model we compare the modified react code to $N$-body simulations and we find agreement within 5% for a wide range of scales and redshifts. We then study the relevant effects of the modifications introduced by the GCCG on the nonlinear matter power spectrum. Finally, we provide forecasts from spectroscopic and photometric primary probes by next generation surveys using a Fisher matrix method. We show that future data will be able to constrain at $1\ensuremath{\sigma}$ the two additional parameters of the model at the percent level and that considering nonlinear corrections to the matter power spectrum beyond the linear regime is crucial to obtain this result.

Authors 5

1. Luís Atayde

   Institute of Astrophysics and Space Sciences

   Affiliation as printed

   Instituto de Astrofisíca e Ciências do Espaço

2. Noemi Frusciante

   University of Naples Federico II

   Affiliation as printed

   Università degli Studi di Napoli “Federico II

3. Benjamin Bose

   Royal Observatory · University of Edinburgh

   Affiliation as printed

   Basic Research Community for Physics e.V

   Royal Observatory

   Basic Research Community for Physics e.V., Veddeler Bruckenstrasse 122, 20539 Hamburg, Germany

   Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, United Kingdom

4. Santiago Casas Aachen Institute for Theoretical Particle Physics and Cosmology

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

   Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, 52056, Aachen, Germany

5. Baojiu Li

   Durham University

   Affiliation as printed

   Durham University

   Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom