Cosmological gravity on all scales III: non-linear matter power spectrum in phenomenological modified gravity

Abstract

Model-independent tests of gravity with cosmology are important when testing extensions to the standard cosmological model. To maximise the impact of these tests one requires predictions for the matter power spectrum on non-linear scales. In this work we validate the \texttt{ReACT} approach to the non-linear matter power spectrum against a suite of phenomenological modified gravity N-body simulations with a time-varying gravitational constant, covering a wider range of parameter space than previously examined. This vanilla application of \texttt{ReACT} has limited range and precision due to the different concentration-mass relation $c(M)$ that occurs when gravity is modified. We extend this approach with a fitting function for a modified concentration-mass relation, allowing for accurate (1$\%$) computation of the matter power spectrum up $k=2h{\mathrm{Mpc}}^{-1}$ across a substantial range of parameter space. This fitting function allows precision model-independent tests of modified gravity to be carried out using the data from upcoming large scale structure surveys.

28 pages, 13 figures Comments Welcome!

References in corpus (17)

• A Parameterized Post-Friedmann Framework for Modified Gravity
• A unifying description of dark energy
• Accurate estimators of power spectra in N-body simulations
• On the road to percent accuracy IV: ReACT -- computing the non-linear power spectrum beyond $\Lambda$CDM
• Realistic simulations of galaxy formation in f(R) modified gravity
• Large Synoptic Survey Telescope: Dark Energy Science Collaboration
• FORGE -- the f(R) gravity cosmic emulator project I: Introduction and matter power spectrum emulator
• On the road to percent accuracy V: the non-linear power spectrum beyond $\Lambda$CDM with massive neutrinos and baryonic feedback
• A parametrisation of modified gravity on nonlinear cosmological scales
• A general framework to test gravity using galaxy clusters II: A universal model for the halo concentration in $f(R)$ gravity
• Cosmological gravity on all scales II: Model independent modified gravity $N$-body simulations
• Current constraints on deviations from General Relativity using binning in redshift and scale
• A general framework to test gravity using galaxy clusters IV: Cluster and halo properties in DGP gravity
• On the degeneracies between baryons, massive neutrinos and f(R) gravity in Stage IV cosmic shear analyses
• Towards an accurate model of small-scale redshift-space distortions in modified gravity
• Nonlinearities in modified gravity cosmology. II. Impacts of modified gravity on the halo properties
• Scale-Dependent Gravitational Couplings in Parameterised Post-Newtonian Cosmology

Cited by in corpus (3)

• Principal Components for Model-Agnostic Modified Gravity with 3x2pt
• Cosmological gravity on all scales IV: 3x2pt Fisher forecasts for pixelised phenomenological modified gravity
• Cosmological gravity on all scales V: MCMC forecasts combining large scale structure and CMB lensing for binned phenomenological modified gravity