Testing gravity with non-Gaussianity

Abstract

We show that modified gravity presents distinctive nonlinear features on the Cosmic Microwave Background (CMB) anisotropies comparing with General Relativity (GR). We calculate the contribution to the CMB non-Gaussianity from nonlinear Sachs-Wolfe effect in $f(R)$ gravity and show that, contrary to GR's contribution which is typically $\lesssim \mathcal{O}(1)$, the contribution in $f(R)$ gravity is sensitive to the nonlinear structure of $f(R)$ and can be large in principle. Optimistically, this gives an alternative origin for the possibly observed large CMB non-Gaussianities besides the primordial ones. On the other hand, such nonlinear features can be employed to provide a new cosmological test of $f(R)$ or other modified theories of gravitation, which is unique and independent of previously known tests.

4 pages, 1 figure, v2 to match the published version

References in corpus (51)

• f(R) Theories Of Gravity
• f(R) theories
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Is Cosmic Speed-Up Due to New Gravitational Physics?
• Modified gravity with negative and positive powers of the curvature: unification of the inflation and of the cosmic acceleration
• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Non-Gaussianity from Inflation: Theory and Observations
• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• A general proof of the conservation of the curvature perturbation
• The inflationary prediction for primordial non-gaussianity
• The Confrontation between General Relativity and Experiment
• The Large Scale Structure of f(R) Gravity
• Relativistic second-order perturbations of the Einstein-de Sitter Universe
• Primordial non-gaussianities in single field inflation
• Constraining f(R) Gravity as a Scalar Tensor Theory
• Quintessence without scalar fields
• Dark Energy Anisotropic Stress and Large Scale Structure Formation
• The pattern of growth in viable f(R) cosmologies
• The Cosmology of f(R) Gravity in the Metric Variational Approach
• f(R) Gravity and Chameleon Theories
• Dynamics of Linear Perturbations in f(R) Gravity
• Cosmological Tests of Gravity
• Stability of Cosmological Solution in f(R) Models of Gravity
• Cluster Constraints on f(R) Gravity
• The Separate Universe Approach and the Evolution of Nonlinear Superhorizon Cosmological Perturbations
• Testing Gravity Against Early Time Integrated Sachs-Wolfe Effect
• Evolution of second-order cosmological perturbations
• Testing General Relativity with Current Cosmological Data
• Weak Lensing Probes of Modified Gravity
• Conserved cosmological perturbations
• Cosmological Constraints on f(R) Acceleration Models
• Modified-Source Gravity and Cosmological Structure Formation
• Newton law corrections and instabilities in $f(R)$ gravity with the effective cosmological constant epoch
• Non-gaussianity from the second-order cosmological perturbation
• CMB Anisotropies at Second Order I
• Density perturbations in f(R) gravity theories in metric and Palatini formalisms
• Higher-Order Gravitational Perturbations of the Cosmic Microwave Background
• CMB Anisotropies at Second-Order II: Analytical Approach
• Gauge-Invariant Temperature Anisotropies and Primordial Non-Gaussianity
• Cosmic Microwave Background anisotropies from second order gravitational perturbations
• The cosmic microwave background bispectrum from the non-linear evolution of the cosmological perturbations
• The radiative transfer at second order: a full treatment of the Boltzmann equation with polarization
• Non-Gaussianity of quantum fields during inflation
• The effect of modified gravity on weak lensing
• Sachs-Wolfe at second order: the CMB bispectrum on large angular scales
• Cosmic microwave background bispectrum on small angular scales
• CMB anisotropies at second order III: bispectrum from products of the first-order perturbations
• Conformal Transformations in Cosmology of Modified Gravity: the Covariant Approach Perspective
• The radiative transfer for polarized radiation at second order in cosmological perturbations
• Cosmological influence of super-Hubble perturbations
• CMB temperature anisotropies from third order gravitational perturbations

Cited by in corpus (6)

• Constraining chameleon models with cosmology
• The intrinsic bispectrum of the Cosmic Microwave Background [PhD thesis]
• Decoding the bispectrum of single-field inflation
• Production of non-gaussianities in a bouncing phase
• Non-Gaussianity from Compositeness
• The intrinsic bispectrum of the CMB from isocurvature initial conditions