Testing the theory of gravity with DESI: estimators, predictions and simulation requirements
Creators: name: Alam, Shadab
name: Arnold, Christian
name: Aviles, Alejandro
name: Bean, Rachel
name: Cai, Yan-Chuan
name: Cautun, Marius
name: Cervantes-Cota, Jorge L.
name: Cuesta-Lazaro, Carolina
name: Devi, N. Chandrachani
name: Eggemeier, Alexander
name: Fromenteau, Sebastien
name: Gonzalez-Morales, Alma X.
name: Halenka, Vitali
name: He, Jian-hua
name: Hellwing, Wojciech A.
name: Hernandez-Aguayo, Cesar
name: Ishak, Mustapha
name: Koyama, Kazuya
name: Li, Baojiu
name: de la Macorra, Axel
name: Rizo, Jennifer Menesses
name: Miller, Christopher
name: Mueller, Eva-Maria
name: Niz, Gustavo
name: Ntelis, Pierros
name: Otero, Matias Rodriguez
name: Sabiu, Cristiano G.
name: Slepian, Zachary
name: Stark, Alejo
name: Valenzuela, Octavio
name: Valogiannis, Georgios
name: Vargas-Magana, Mariana
name: Winther, Hans A.
name: Zarrouk, Pauline
name: Zhao, Gong-Bo
name: Zheng, Yi
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Shortly after its discovery, General Relativity (GR) was applied to predict the behavior of our Universe on the largest scales, and later became the foundation of modern cosmology. Its validity has been verified on a range of scales and environments from the Solar system to merging black holes. However, experimental confirmations of GR on cosmological scales have so far lacked the accuracy one would hope for -- its applications on those scales being largely based on extrapolation and its validity sometimes questioned in the shadow of the unexpected cosmic acceleration. Future astronomical instruments surveying the distribution and evolution of galaxies over substantial portions of the observable Universe, such as the Dark Energy Spectroscopic Instrument (DESI), will be able to measure the fingerprints of gravity and their statistical power will allow strong constraints on alternatives to GR. In this paper, based on a set of $N$-body simulations and mock galaxy catalogs, we study the predictions of a number of traditional and novel estimators beyond linear redshift distortions in two well-studied modified gravity models, chameleon $f(R)$ gravity and a braneworld model, and the potential of testing these deviations from GR using DESI. These estimators employ a wide array of statistical properties of the galaxy and the underlying dark matter field, including two-point and higher-order statistics, environmental dependence, redshift space distortions and weak lensing. We find that they hold promising power for testing GR to unprecedented precision. The major future challenge is to make realistic, simulation-based mock galaxy catalogs for both GR and alternative models to fully exploit the statistic power of the DESI survey and to better understand the impact of key systematic effects. Using these, we identify future simulation and analysis needs for gravity tests using DESI.
description: 69 pages, 36 figures, 6 tables; accepted for publication in JCAP. The modified gravity HOD galaxy catalogues used in this paper can be downloaded from http://icc.dur.ac.uk/data/, by searching for the title of this paper from the dataset table