The kinematic Sunyaev–Zel’dovich effect of the large-scale structure (II): the effect of modified gravity

Abstract

The key to understand the nature of dark energy relies in our ability to probe the distant Universe. In this framework, the recent detection of the kinematic Sunyaev-Zel'dovich (kSZ) effect signature in the cosmic microwave background obtained with the South Pole Telescope (SPT) is extremely useful since this observable is sensitive to the high-redshift diffuse plasma. We analyse a set of cosmological hydrodynamical simulation with 4 different realisations of a Hu & Sawicki f (R) gravity model, parametrised by the values of f R,0 = (0, −10 −6 , −10 −5 , −10 −4 ), to compute the properties of the kSZ effect due to the ionized Universe and how they depend on f R,0 and on the redshift of reionization, z re . In the standard General Relativity limit ( f R,0 =0) we obtain an amplitude of the kSZ power spectrum of D kSZ 3000 = 4.1 µK 2 (z re =8.8), close to the +1σ limit of the D kSZ 3000 = (2.9 ± 1.3) µK 2 measurement by SPT. This corresponds to an upper limit on the kSZ contribute from patchy reionization of D kSZ,patchy 3000 < 0.9 µK 2 (95 per cent confidence level). Modified gravity boosts the kSZ signal by about 3, 12 and 50 per cent for f R,0 = (−10 −6 , −10 −5 , −10 −4 ), respectively, with almost no dependence on the angular scale. This means that with modified gravity the limits on patchy reionization shrink significantly: for f R,0 = −10 −5 we obtain D kSZ,patchy 3000 < 0.4 µK 2 . Finally, we provide an analytical formula for the scaling of the kSZ power spectrum with z re and f R,0 at different multipoles: at ℓ = 3000 we obtain D kSZ 3000 ∝ z re 0.24 1 + f R,0 41.

A general framework to test gravity using galaxy clusters III: observable-mass scaling relations in f(R) gravity

“…The model is a modification of GR, which introduces an extra scalar field that couples to matter, giving rise to a 'fifth force' which enhances the total strength of gravity. Past works have used various cluster properties to probe 𝑓 (𝑅) gravity, including: number counts (e.g., Cataneo et al 2015;Liu et al 2016;Peirone et al 2017); the clustering of clusters (Arnalte-Mur et al 2017); redshift-space distortions (e.g., Bose & Koyama 2017;He et al 2018;Hernández-Aguayo et al 2019;García-Farieta et al 2021); the gas mass fraction (e.g., Li et al 2016); the temperature-mass relation (see, e.g., Hammami & Mota 2017;Del Popolo et al 2019); the SZ profile (De Martino 2016); comparisons of weak lensing data with thermal observables (e.g., Terukina et al 2014;Wilcox et al 2015); and the angular power spectra of the thermal and kinetic SZ effects (e.g., Ma & Zhao 2014;Bianchini & Silvestri 2016;Roncarelli et al 2018;Mitchell et al 2021c).…”

The impact of modified gravity on the Sunyaev-Zel'dovich effect

“…The enhancement of the kSZ power by ∼ 22% in F5 is higher than predicted by Bianchini & Silvestri (2016) and Roncarelli et al (2018), who estimated an enhancement of about 15% for the same model using analytical predictions and hydrodynamical simulations, respectively. We remark that our results use only the redshift range 𝑧 ≤ 3 while these works used redshifts up to 9.9 and 15, including the epoch of reionisation which can have a substantial contribution to the total kSZ power.…”

“…A number of works have made use of the tSZ power spectrum to constrain cosmological parameters including the dimensionless matter density Ω M , the linear density fluctuation 𝜎 8 , the dark energy equation of state parameter and the neutrino mass (e.g., Horowitz & Seljak 2017;Hurier & Lacasa 2017;Bolliet et al 2018;Salvati et al 2018). Meanwhile, as the precision of measurements of the kSZ power continues to improve, a number of works have identified this as a promising probe for future constraints of dark energy and ★ E-mail: m.a.mitchell@durham.ac.uk MG theories (e.g., Ma & Zhao 2014;Bianchini & Silvestri 2016;Roncarelli et al 2018). The wealth of high-quality observational data coming from current and upcoming surveys (e.g., Sievers et al 2013;Aghanim et al 2016;George et al 2015;Reichardt et al 2020;Ade et al 2019;Abazajian et al 2016) for both the tSZ and kSZ effects make it an exciting time for this growing area.…”

Pairwise Transverse Velocity Measurement with the Rees–Sciama Effect

“…This is obtained either through the inspection of galaxies' spectra, or via the study of the kinetic Sunyaev-Zeldovich (kSZ) effect (Sunyaev & Zeldovich 1972) in CMB maps (see, e.g. Mroczkowski et al (2018); Roncarelli et al (2017Roncarelli et al ( , 2018; Bhattacharya & Kosowsky (2008); Hill et al (2016); Mak et al (2011)). The amplitude of the kSZ is ∼ 1µK and hence subdominant to the primary CMB fluctuations at 4000, however, it is possible to increase its signal-to-noise ratio (S/N) using a differential (pairwise) measurement; averaging the pairwise kSZ signal over several pairs naturally produces a cancellation of noise sources.…”