Dr Sim’s research interests lie in the numerical modelling of radiation transport and spectral synthesis. His studies have included applications to stellar chromospheres/coronae, hot star winds, outflows from accreting systems, and supernovae.

Currently, the focus of his work is in the development and testing of theoretical models for thermonuclear supernova explosions. In particular, he develops Monte Carlo radiative transfer simulations that allow synthetic light curves, spectra and spectropolarimetry to be computed and used to interpret observational data and constrain explosion theories.