A diverse set of observations now compellingly suggest that the universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the favored value for the cosmological constant corresponds to a very tiny vacuum energy density. We discuss future observational tests for a cosmological constant as well as the fundamental theoretical challenges - and opportunities - that this poses for particle physics and for extending our understanding of the evolution of the universe back to the earliest moments.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)