Large scale structure as a probe of gravitational slip

A new time-dependent, scale-independent parameter, $\ensuremath{\varpi}$, 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 $\ensuremath{\varpi}$ and other parametrized post-Friedmannian models in the literature. The effect of $\ensuremath{\varpi}$ 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.