A general framework to test gravity using galaxy clusters I: Modelling the dynamical mass of haloes in $ f(R) $ gravity
| Autor: | Jian-hua He, Myles A. Mitchell, Christian Arnold, Baojiu Li |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics
Gravity (chemistry) Cosmology and Nongalactic Astrophysics (astro-ph.CO) Field (physics) 010308 nuclear & particles physics Dark matter FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Redshift Theoretical physics Space and Planetary Science 0103 physical sciences Dark energy f(R) gravity 010303 astronomy & astrophysics Scalar field Galaxy cluster Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society |
| Popis: | We propose a new framework for testing gravity using cluster observations, which aims to provide an unbiased constraint on modified gravity models from Sunyaev Zel'dovich (SZ) and X-ray cluster counts and the cluster gas fraction, among other possible observables. Focusing on a popular $ f(R) $ model of gravity, we propose a novel procedure to recalibrate mass scaling relations from $ \Lambda $CDM to $ f(R) $ gravity for SZ and X-ray cluster observables. We find that the complicated modified gravity effects can be simply modelled as a dependence on a combination of the background scalar field and redshift, $ f_R(z)/(1+z) $, regardless of the $ f(R) $ model parameter. By employing a large suite of N-body simulations, we demonstrate that a theoretically derived tanh fitting formula is in excellent agreement with the dynamical mass enhancement of dark matter haloes for a large range of background field parameters and redshifts. Our framework is sufficiently flexible to allow for tests of other models and inclusion of further observables. The one-parameter description of the dynamical mass enhancement can have important implications on the theoretical modelling of observables and on practical tests of gravity. Comment: 20 pages, 10 figures, 1 table |
| Databáze: | OpenAIRE |
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