Burning regimes for thermonuclear supernovae and cosmological applications of SNe Ia

Abstract

The method of multigroup radiation hydrodynamics is used to compute light curves for thermonuclear supernovae. Opacities are computed by taking into account spectral lines and expansion. UBVI fluxes are predicted. Our computed times of brightness rise to a maximum in B and V have been found to agree with observations better than those of other authors. The validity of our results is justified physically. The nuclear burning regime is shown to affect significantly the slope of the light curve in B and, to a slightly lesser extent, in V. If the prevailing burning regime during supernova explosions changed with age of the Universe, then the conclusion about a positive cosmological constant Λ drawn from observations of Type Ia supernovae may prove to be wrong.