Measuring anisotropic stress with relativistic effects

Abstract

One of the main goal of large-scale structure surveys is to test the consistency of General Relativity at cosmological scales. In the $\Lambda$CDM model of cosmology, the relations between the fields describing the geometry and the content of our Universe are uniquely determined. In particular, the two gravitational potentials -- that describe the spatial and temporal fluctuations in the geometry -- are equal. Whereas large classes of dark energy models preserve this equality, theories of modified gravity generally create a difference between the potentials, known as anisotropic stress. Even though measuring this anisotropic stress is one of the key goals of large-scale structure surveys, there are currently no methods able to measure it directly. Current methods all rely on measurements of galaxy peculiar velocities (through redshift-space distortions), from which the time component of the metric is inferred, assuming that dark matter follows geodesics. If this is not the case, all the proposed tests fail to measure the anisotropic stress. In this letter, we propose a novel test which directly measures anisotropic stress, without relying on any assumption about the unknown dark matter. Our method uses relativistic effects in the galaxy number counts to provide a direct measurement of the time component of the metric. By comparing this with lensing observations our test provides a direct measurement of the anisotropic stress.

arXiv comment6 pages, no figures. V2 is the published version

References in corpus (54)

• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• Overview of the DESI Legacy Imaging Surveys
• Dark Energy Survey Year 1 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• KiDS-1000 Cosmology: Cosmic shear constraints and comparison between two point statistics
• Planck 2018 results. VIII. Gravitational lensing
• The linear power spectrum of observed source number counts
• What galaxy surveys really measure
• A discriminating probe of gravity at cosmological scales
• Weak Lensing and Cosmology
• New Perspective on Galaxy Clustering as a Cosmological Probe: General Relativistic Effects
• The Bispectrum as a Signature of Gravitational Instability in Redshift-Space
• Large-scale clustering of galaxies in general relativity
• The WiggleZ Dark Energy Survey: Final data release and cosmological results
• Detection of Cosmic Magnification with the Sloan Digital Sky Survey
• Anisotropic stress as signature of non-standard propagation of gravitational waves
• Dark Energy Survey Year 3 Results: Weak Lensing Shape Catalogue
• Planck 2015 results. XXI. The integrated Sachs-Wolfe effect
• Observables and unobservables in dark energy cosmologies
• The CLASSgal code for Relativistic Cosmological Large Scale Structure
• gevolution: a cosmological N-body code based on General Relativity
• Testing General Relativity on Horizon Scales and the Primordial non-Gaussianity
• Going beyond the Kaiser redshift-space distortion formula: a full general relativistic account of the effects and their detectability in galaxy clustering
• The Atacama Cosmology Telescope: Two-Season ACTPol Lensing Power Spectrum
• Asymmetric galaxy correlation functions
• Dark Energy Survey Year 1 Results: Galaxy-Galaxy Lensing
• A Measurement of the Cosmic Microwave Background Lensing Potential and Power Spectrum from 500 deg${}^2$ of SPTpol Temperature and Polarization Data
• Gravitational redshift and other redshift-space distortions of the imaginary part of the power spectrum
• Measurement of the dipole in the cross-correlation function of galaxies
• Constraining Gravity at the Largest Scales through CMB Lensing and Galaxy Velocities
• Relativistic N-body simulations with massive neutrinos
• Single-Field Consistency Relations of Large Scale Structure. Part III: Test of the Equivalence Principle
• Euclid preparation: VII. Forecast validation for Euclid cosmological probes
• Model-independent constraints on the cosmological anisotropic stress
• Testing the equivalence principle on cosmological scales
• Model-independent reconstruction of the linear anisotropic stress $\eta$
• Consequences of Symmetries and Consistency Relations in the Large-Scale Structure of the Universe for Non-local bias and Modified Gravity
• Optimising the measurement of relativistic distortions in large-scale structure
• Modeling relativistic contributions to the halo power spectrum dipole
• Probing Dark Energy through Scale Dependence
• Combining weak lensing tomography and spectroscopic redshift surveys
• Measuring Gravitational Redshifts in Galaxy Clusters
• On the importance of lensing for galaxy clustering in photometric and spectroscopic surveys
• Gravitational redshifts from large-scale structure
• Measuring cosmic velocities with 21cm intensity mapping and galaxy redshift survey cross-correlation dipoles
• Hints of dark energy anisotropic stress using Machine Learning
• Gravity theories, Transverse Doppler and Gravitational Redshifts in Galaxy Clusters
• Weak lensing magnification in the Dark Energy Survey Science Verification Data
• Measurement of the Cosmic Microwave Background Polarization Lensing Power Spectrum from Two Years of POLARBEAR Data
• Gravitational redshift and asymmetric redshift-space distortions for stacked clusters
• Higher order relativistic galaxy number counts: dominating terms
• A null test of the equivalence principle using relativistic effects in galaxy surveys
• A null test to probe the scale-dependence of the growth of structure as a test of General Relativity
• General Relativistic corrections in density-shear correlations
• The observable $E_g$ statistics

Cited by in corpus (13)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Machine learning constraints on deviations from general relativity from the large scale structure of the Universe
• Gravitational Redshift Constraints on the Effective Theory of Interacting Dark Energy
• Modified Einstein versus Modified Euler for Dark Matter
• Combining gravitational lensing and gravitational redshift to measure the anisotropic stress with future galaxy surveys
• Testing gravity with gravitational wave friction and gravitational slip
• Measuring the distortion of time with relativistic effects in large-scale structure
• Disentangling modified gravity from a dark force with gravitational redshift
• Euclid: Relativistic effects in the dipole of the 2-point correlation function
• Using relativistic effects in large-scale structure to constrain astrophysical properties of galaxy populations
• Model-Independent Test for Gravity using Intensity Mapping and Galaxy Clustering
• Lensing convergence and anisotropic dark energy in galaxy redshift surveys
• A Light-Cone Approach to Higher-Order Cosmological Observables