  Thermonuclear supernovae are valuable for cosmology but their physics is not
yet fully understood. Modeling the development and propagation of nuclear flame
is complicated by numerous instabilities. The predictions of supernova light
curves still involve some simplifying assumptions, but one can use the
comparison of the computed fluxes with observations to constrain the explosion
mechanism. In spite of great progress in recent years, a number of issues
remains unsolved both in flame physics and light curve modeling.
