fkPT: Constraining scale-dependent modified gravity with the full-shape galaxy power spectrum
| Autor: | Rodriguez-Meza, Mario A., Aviles, Alejandro, Noriega, Hernan E., Ruan, Cheng-Zong, Li, Baojiu, Vargas-Magaña, Mariana, Cervantes-Cota, Jorge L. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | JCAP03(2024)049 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1475-7516/2024/03/049 |
| Popis: | Modified gravity models with scale-dependent linear growth typically exhibit an enhancement in the power spectrum beyond a certain scale. The conventional methods for extracting cosmological information usually involve inferring modified gravity effects via Redshift Space Distortions (RSD), particularly through the time evolution of $f\sigma_8$. However, classical galaxy RSD clustering analyses encounter difficulties in accurately capturing the spectrum's enhanced power, which is better obtained from the broad-band power spectrum. In this sense, full-shape analyses aim to consider survey data using comprehensive and precise models of the whole power spectrum. Yet, a major challenge in this approach is the slow computation of non-linear loop integrals for scale-dependent modified gravity, precluding the estimation of cosmological parameters using Markov Chain Monte Carlo methods. Based on recent studies, in this work we develop a perturbation theory tailored for Modified Gravity, or analogous scenarios introducing additional scales, such as in the presence of massive neutrinos. Our approach only needs the calculation of the scale-dependent growth rate $f(k,t)$ and the limit of the perturbative kernels at large scales. We called this approximate technique as fk-Perturbation Theory and implemented it into the code fkpt, capable of computing the redshift space galaxy power spectrum in a fraction of a second. We validate our modeling and code with the $f(R)$ theory MG-GLAM and General Relativity NSeries sets of simulations. The code is available at https://github.com/alejandroaviles/fkpt Comment: 34 pages, 9 figures. v2 |
| Databáze: | arXiv |
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