Characterize the orbital-period distribution of white-dwarf exoplanets

Characterize the underlying orbital-period distribution of white-dwarf exoplanets so that Roman Galactic Bulge Time Domain Survey yield predictions can be refined beyond the assumed log-uniform period prior.

Background

The predicted Roman yield varies by approximately a factor of six between the period-averaged estimate and the sensitivity at the shortest periods. Close-in planets produce many more expected detections than long-period planets, while population-synthesis models also predict that many surviving white-dwarf companions occupy wide orbits. Because the actual period distribution is not established, the paper presents its period-averaged yields using a log-uniform prior and provides a period-resolved detection grid that can be refolded once observational constraints become available.