'Steckbrief' Lambda

Abstract

The phenomenology of the FLRW models with non-vanishing cosmological constant (CC) is briefly surveyed in the light of the recent astrophysical and cosmological observations. A subset of these models, which probably includes the world where we live, is singled out by the combined data from high redshift Type Ia supernovae, CMBR and the cosmic inventory of matter in our universe. The kinematical success of a non-vanishing CC, however, leaves open many dynamical questions in quantum field theory. A semiclassical renormalization group approach to the CC might perhaps shed some light on them. In this context, the CC is naturally non-zero simply because it is a running parameter.