Astrophysical fluid dynamics with emphasis on convective dynamics and scale selection, turbulence, the excitation of the solar/stellar p-modes, and the origin of solar/stellar irradiance variations. Investigations range from studying highly simplified turbulent analogs based on point vortex motions to highly realistic simulations of radiative magnetohydrodynamics, spectral synthesis, and spectropolarimetric inversions. Led the development of the Critical Science Plan for the National Solar Observatory's (NSO's) 4m solar telescope, the Daniel K. Inouye Solar Telescope (DKIST). Recent work, motivated by the SARS-CoV-2 pandemic, focuses on contact statistics in random walks and turbulent flows.
Rast, M.P. & Pinton, J.-F. 2011, “Pair dispersion in turbulence: the subdominant role of scaling,” PRL 107, 214501.
Rast, M.P., Pinton, J.-F., & Mininni, P.D. 2016. "Turbulent transport with intermittency: Expectation of a scalar concentration," PhysRevE 93, 043120.
Agrawal, P., Rast, M.P., Gossip, M., Bellot Rubio, L.R., & Rempel, M. 2018, "Transport of internetwork magnetic flux elements in the solar photosphere," ApJ 854, 118.
Rast, M.P. 2022, "Contact statistics in populations of noninteracting random walkers in two dimensions," PhysRevE 105, 014103.