Large Scale Structure as a Probe of Gravitational Slip

TL;DR

This paper introduces a new parameter  to model deviations from General Relativity on cosmological scales, analyzing its effects on cosmic microwave background, large-scale structure, and lensing, and comparing it with existing models.

Contribution

It proposes a novel, scale-independent parameter  for gravitational slip, and assesses its impact on cosmological observations, providing a new phenomenological framework.

Findings

 affects CMB anisotropy spectrum and structure growth.

Models with conventional parameters align with a narrow  range.

Comparison with other models highlights differences in gravitational slip modeling.

Abstract

A new time-dependent, scale-independent parameter, \varpi, is employed in a phenomenological model of the deviation from General Relativity in which the Newtonian and longitudinal gravitational potentials slip apart on cosmological scales as dark energy, assumed to be arising from a new theory of gravitation, appears to dominate the universe. A comparison is presented between \varpi and other parameterized post-Friedmannian models in the literature. The effect of \varpi on the cosmic microwave background anisotropy spectrum, the growth of large scale structure, the galaxy weak-lensing correlation function, and cross-correlations of cosmic microwave background anisotropy with galaxy clustering are illustrated. Cosmological models with conventional maximum likelihood parameters are shown to find agreement with a narrow range of gravitational slip.