PROFESSOR SHASHI KANBUR

The Cepheid Period-Luminosity relation is of paramount importance in developing an extra-galactic distance scale that is independent of the Cosmic Microwave Background. Developing such an independent distance scale that is accurate to less than 3% is important in placing constraints on the dark energy equation of state. For the last 70 years, the assumption has been that the PL relation is linear. Here we review recent evidence supporting a nonlinear PL relation, the impact on estimates of Hubble's constant and on stellar pulsation and also comment on recent advances in the statistical description of the quantitative structure on variable star light curves.