Predictions for Strong-lens Detections with the Nancy Grace Roman Space Telescope

Abstract Strong gravitational lensing is an ideal tool for mapping the distribution of dark matter and for testing the values of cosmological parameters. Forthcoming surveys such as Euclid and the Rubin Observatory Large Synoptic Telescope Survey should increase the number of known strong lensing systems significantly, with for example over 100,000 such systems predicted in the Euclid wide survey. In this short research note we predict that approximately 17,000 strong gravitational lenses will also be detectable in the Nancy Grace Roman Space Telescope 2000 square degree survey, using the LensPop gravitational lensing model. We present predicted distributions in source and deflector redshifts, magnitudes, and magnifications. Although this survey is not primarily designed as a strong lensing detection experiment, it will still provide a large complementary catalog to shallower, wider-area forthcoming lensing discovery projects.