Galaxy morphology rules out astrophysically relevant Hu-Sawicki f (R) gravity
Physical Review D American Physical Society 102:10 (2020) 104060
Abstract:
f ( R ) is a paradigmatic modified gravity theory that typifies extensions to General Relativity with new light degrees of freedom and hence screened fifth forces between masses. These forces produce observable signatures in galaxy morphology, caused by a violation of the weak equivalence principle due to a differential impact of screening among galaxies’ mass components. We compile statistical datasets of two morphological indicators—offsets between stars and gas in galaxies and warping of stellar disks—and use them to constrain the strength and range of a thin-shell-screened fifth force. This is achieved by applying a comprehensive set of upgrades to past work [H. Desmond et al., Phys. Rev. D 98, 064015 (2018); H. Desmond et al., Phys. Rev. D 98, 083010 (2018) ]: we construct a robust galaxy-by-galaxy Bayesian forward model for the morphological signals, including full propagation of uncertainties in the input quantities and marginalization over an empirical model describing astrophysical noise. Employing more stringent data quality cuts than previously we find no evidence for a screened fifth force of any strength Δ G / G N in the Compton wavelength range 0.3–8 Mpc, setting a 1 σ bound of Δ G / G N < 0.8 at λ C = 0.3 Mpc that strengthens to Δ G / G N < 3 × 10 − 5 at λ C = 8 Mpc . These are the tightest bounds to date beyond the Solar System by over an order of magnitude. For the Hu-Sawicki model of f ( R ) with n = 1 we require a background scalar field value f R 0 < 1.4 × 10 − 8 , forcing practically all astrophysical objects to be screened. We conclude that this model can have no relevance to astrophysics or cosmology.Galaxy morphology rules out astrophysically relevant Hu-Sawicki f (R) gravity
PHYSICAL REVIEW D American Physical Society (APS) 102:10 (2020) ARTN 104060
Growth of accretion driven scalar hair around Kerr black holes
(2020)
The SAMI Galaxy Survey: a statistical approach to an optimal classification of stellar kinematics in galaxy surveys
(2020)
Developing a unified pipeline for large-scale structure data analysis with angular power spectra -- III. Implementing the multi-tracer technique to constrain neutrino masses
Monthly Notices of the Royal Astronomical Society, Volume 502, Issue 2, April 2021, Pages 2952–2960
Abstract:
In this paper, we apply the multitracer technique to harmonic-space (i.e. angular) power spectra with a likelihood-based approach. This goes beyond the usual Fisher matrix formalism hitherto implemented in forecasts with angular statistics, opening up a window for future developments and direct application to available data sets. We also release a fully operational modified version of the publicly available code CosmoSIS, where we consistently include all the add-ons presented in the previous papers of this series. The result is a modular cosmological parameter estimation suite for angular power spectra of galaxy number counts, allowing for single and multiple tracers, and including density fluctuations, redshift-space distortions, and weak-lensing magnification. We demonstrate the improvement on parameter constraints enabled by the use of multiple tracers on a multitracing analysis of luminous red galaxies and emission-line galaxies. We obtain an enhancement of 44 per cent on the 2σ upper bound on the sum of neutrino masses.