Multiprobe strategies for Kinematic Lensing with the Roman Space Telescope High Latitude Wide Area Survey

Abstract

In its latest design, the High Latitude Wide Area Survey (HLWAS) Medium Tier comprises overlapping photometric and spectroscopic data across 2,300 square degrees. This dataset enables Kinematic Lensing (KL), a Weak Lensing (WL) technique that exploits galaxy kinematics to control for shape noise, the dominant statistical limitation of traditional WL. We present several simulated analyses quantifying the expected cosmological science return of a Roman KL analysis with the latest design of the HLWAS: We explore KL prospects with early Roman data from the Deep Tier fields and from the early Medium Tier fields; we demonstrate the impact of different roll-angle choices on the KL performance; we benchmark KL against traditional WL; we introduce a KL-based multiprobe analysis that jointly models KL, galaxy clustering, and galaxy-galaxy lensing. In these analyses, we consider systematics, including photometric uncertainties, shear calibration bias, galaxy bias, and baryonic feedback. Our results show that KL alone achieves a dark energy figure of merit (FoM) of 22.54, which is more than a factor of two improvement over a corresponding WL analysis. The KL multiprobe approach improves the full-survey FoM to 34.58, even assuming conservative scale cuts in the clustering and galaxy-galaxy lensing. For the HLWAS roll-angle strategy, we find that the current plan of 4 passes with rotations of approximately 0, 10, 170, 180 degrees are near optimal for KL.