Galaxy-galaxy weak gravitational lensing in $f(R)$ gravity

Abstract

We present an analysis of galaxy-galaxy weak gravitational lensing (GGL) in chameleon $f(R)$ gravity - a leading candidate of non-standard gravity models. For the analysis we have created mock galaxy catalogues based on dark matter haloes from two sets of numerical simulations, using a halo occupation distribution (HOD) prescription which allows a redshift dependence of galaxy number density. To make a fairer comparison between the $f(R)$ and $\Lambda$CDM models, their HOD parameters are tuned so that the galaxy two-point correlation functions in real space (and therefore the projected two-point correlation functions) match. While the $f(R)$ model predicts an enhancement of the convergence power spectrum by up to $\sim 30\%$ compared to the standard $\Lambda$CDM model with the same parameters, the maximum enhancement of GGL is only half as large and less than 5\% on separations above $\sim 1$-$2h^{-1}$Mpc, because the latter is a cross correlation of shear (or matter, which is more strongly affected by modified gravity) and galaxy (which is weakly affected given the good match between galaxy auto correlations in the two models) fields. We also study the possibility of reconstructing the matter power spectrum by combination of GGL and galaxy clustering in $f(R)$ gravity. We find that the galaxy-matter cross correlation coefficient remains at unity down to $\sim 2$-$3h^{-1}$Mpc at relevant redshifts even in $f(R)$ gravity, indicating joint analysis of GGL and galaxy clustering can be a powerful probe of matter density fluctuations in chameleon gravity. The scale dependence of the model differences in their predictions of GGL can potentially allow to break the degeneracy between $f(R)$ gravity and other cosmological parameters such as ${\Omega }_m$ and ${\sigma }_8$.

16 pages, 9 figures

References in corpus (13)

• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Beyond the Cosmological Standard Model
• Covariant Galileon
• Healthy theories beyond Horndeski
• Transients from Initial Conditions in Cosmological Simulations
• Evading Equivalence Principle Violations, Cosmological and other Experimental Constraints in Scalar Field Theories with a Strong Coupling to Matter
• f(R) Gravity and Chameleon Theories
• Cosmological perturbations and structure formation in nonlocal infrared modifications of general relativity
• Constraining $f(R)$ Gravity Theory Using Weak Lensing Peak Statistics from the Canada-France-Hawaii-Telescope Lensing Survey
• Impact of Baryonic Processes on Weak Lensing Cosmology: Power Spectrum, Non-Local Statistics, and Parameter Bias
• The imprint of $f(R)$ gravity on weak gravitational lensing II : Information content in cosmic shear statistics
• Constraining f(R) Gravity with Planck Sunyaev-Zel'dovich Clusters
• Can background cosmology hold the key for modified gravity tests?

Cited by in corpus (2)

• Finite-time Cosmological Singularities and the Possible Fate of the Universe
• Realistic simulations of galaxy formation in f(R) modified gravity