Cosmology with supernovae

Modern cosmology is using many different methods to determine the structure of the universe. Supernovae are among the most important ones due to their extreme luminosity, the time-variability that allows to separate the different supernova explosions and relative ease with which they can be observed. Since the recognition of supernovae as a separate class of astrophysical objects they have been proposed and used to measure the distance scale and the geometry of the universe. There are several independent applications with supernovae to measure the current expansion rate, Hubble's constant, and the expansion history of the universe. The latter has led to the surprising discovery that the expansion is actually accelerating and a new component for the universe is needed. Supernovae are also poised to be a major player in the characterisation of the nature of the dark energy.