Magnetohydrodynamics

Ore Gottlieb’s group studies compact objects and high-energy transients through general-relativistic magnetohydrodynamic simulations, analytical models and multimessenger predictions. Topics include black holes, neutron stars, collapsars, stellar explosions, compact-object mergers, gamma-ray bursts, nucleosynthesis and gravitational waves. The researcher can develop independent projects and use leadership-class computing allocations. The benefits-eligible appointment is for two years with a possible third year, beginning flexibly in summer or autumn 2027. Salary is $73,308–$90,000. Applications received by 4 December 2026 receive full consideration; review continues until filled.

Shane Davis presents simulations of stellar disruption and the subsequent return of debris to a black hole. Observed light curves and spectra offer tests of accretion physics and black-hole spacetime, but interpreting them requires accounting for strong radiation forces during rapid fallback. Using Athena++ and AthenaK, the research models radiation transfer, including recent calculations in Kerr spacetime. Although the debris circularizes slowly, shocks involving the returning stream and an eccentric disk dominate early energy release and angular-momentum transport. Radiation drives unbound outflows and builds a weakly bound envelope that reprocesses emission. These results offer an explanation for the strong optical and ultraviolet signals observed in many tidal disruption events.