Dimensionally Regulated Graviton 1-Point Function in de Sitter
  We use dimensional regularization to compute the 1PI 1-point function of quantum gravity at one loop order in a locally de Sitter background. As with other computations, the result is a finite constant at this order. It corresponds to a small positive renormalization of the cosmological constant. 
N. C. Tsamis (University of Crete) and R. P. Woodard (University of   Florida)