Cosmological Density Perturbations with a Scale-Dependent Newton's G

Abstract

We explore possible cosmological consequences of a running Newton's constant $G(\square )$, as suggested by the non-trivial ultraviolet fixed point scenario in the quantum field-theoretic treatment of Einstein gravity with a cosmological constant term. In particular we focus here on what possible effects the scale-dependent coupling might have on large scale cosmological density perturbations. Starting from a set of manifestly covariant effective field equations derived earlier, we systematically develop the linear theory of density perturbations for a non-relativistic, pressure-less fluid. The result is a modified equation for the matter density contrast, which can be solved and thus provides an estimate for the growth index parameter $\gamma$ in the presence of a running $G$. We complete our analysis by comparing the fully relativistic treatment with the corresponding results for the non-relativistic (Newtonian) case, the latter also with a weakly scale dependent $G$.

54 pages, 4 figures

References in corpus (13)

• Measuring the dark side (with weak lensing)
• Cluster Constraints on f(R) Gravity
• A bird's eye view of f(R)-gravity
• The dispersion of growth of matter perturbations in f(R) gravity
• The Observed Growth of Massive Galaxy Clusters III: Testing General Relativity on Cosmological Scales
• The role of Background Independence for Asymptotic Safety in Quantum Einstein Gravity
• A Multi-Parameter Investigation of Gravitational Slip
• Running of Newton's constant and non integer powers of the d'Alembertian
• Gravitational Wilson Loop and Large Scale Curvature
• Renormalization Group Running of Newton's G: The Static Isotropic Case
• Gravitational Wilson Loop in Discrete Quantum Gravity
• Does Planck mass run on the cosmological horizon scale?
• Constraints on Gravitational Scaling Dimensions from Non-Local Effective Field Equations

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