  The Nancy Grace Roman Space Telescope (Roman) is NASA's next astrophysics
flagship mission, expected to launch in late 2026. As one of Roman's core
community science surveys, the Galactic Bulge Time Domain Survey (GBTDS) will
collect photometric and astrometric data for over 100 million stars in the
Galactic bulge to search for microlensing planets. To assess the potential with
which Roman can detect exoplanets via transit, we developed and conducted
pixel-level simulations of transiting planets in the GBTDS. From these
simulations, we predict that Roman will find between $\sim$60,000 and
$\sim$200,000 transiting planets, over an order of magnitude more planets than
are currently known. While the majority of these planets will be giants
($R_p>4R_\oplus$) on close-in orbits ($a<0.3$ au), the yield also includes
between $\sim$7,000 and $\sim$12,000 small planets ($R_p<4 R_\oplus$). The
yield for small planets depends sensitively on the observing cadence and season
duration, with variations on the order of $\sim$10-20% for modest changes in
either parameter, but is generally insensitive to the trade between surveyed
area and cadence given constant slew/settle times. These predictions depend
sensitively on the Milky Way's metallicity distribution function, highlighting
an opportunity to significantly advance our understanding of exoplanet
demographics, particularly across stellar populations and Galactic
environments.
