Gravitational energy in quadratic-curvature gravities
PHYSICAL REVIEW LETTERS, vol.89, no.10, 2002 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 89 Issue: 10
- Publication Date: 2002
- Doi Number: 10.1103/physrevlett.89.101101
- Journal Name: PHYSICAL REVIEW LETTERS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Open Archive Collection: AVESIS Open Access Collection
- Middle East Technical University Affiliated: No
Abstract
We define energy (E) and compute its values for gravitational systems involving terms quadratic in curvature. There are significant differences, both conceptually and concretely, from Einstein theory. For D=4, all purely quadratic models admit constant curvature vacua with arbitrary Lambda, and E is the "cosmological" Abbott-Deser (AD) expression; instead, E always vanishes in flat, Lambda=0, background. For combined Einstein-quadratic curvature systems without explicit Lambda-term vacuum must be flat space, and E has the usual Arnowitt-Deser-Misner form. A Lambda-term forces unique de Sitter vacuum, with E the sum of contributions from Einstein and quadratic parts to the AD form. We also discuss the effects on energy definition of higher curvature terms and of higher dimension.