On the cosmological constant: its identification as renormalization group invariant scale corresponding to a gravitational condensate
Résumé
We examine the general issue of whether a scale dependent cosmological constant can be consistent with general covariance, a problem that arises naturally in the treatment of quantum gravitation where coupling constants generally run as a consequence of renormalization group effects. The issue is approached from several points of view, which include the manifestly covariant functional integral formulation, covariant continuum perturbation theory about two dimensions, and the lattice formulation of gravity. In all cases we find that the cosmological constant cannot run with scale, unless general covariance is explicitly broken by the regularization procedure. This article is based on Int. J. Mod. Phys. D22 (2013) 13, 1330023 [arXiv:1301.6259].