Probing a scale dependent gravitational slip with galaxy strong lensing systems

Understand

Observations of galaxy-scale strong gravitational lensing systems enable unique tests of departures from general relativity at the kpc-Mpc scale.

• In this work, the gravitational slip parameter $\gamma_{\rm PN}$, measuring the amplitude of a hypothetical fifth force, is constrained using 130 elliptical galaxy lens systems.
• We implement a lens model with a power-law total mass density and a deprojected De Vaucouleurs luminosity density, favored over a power-law luminosity density.
• To break the degeneracy between the lens velocity anisotropy, $\beta$, and the gravitational slip, we introduce a new prior on the velocity anisotropy based on recent dynamical data.