2005/04/25 by Sandrine Cnockaert, S. Cnockaert, Marc Henneaux +1 · 10 citations
Mathematics · Physics and Astronomy · #Advanced Differential Geometry Research #BRST quantization #Black Holes and Theoretical Physics #Cohomology #Covariant derivative #Covariant transformation #Curvature #Gauge theory #Geometric Analysis and Curvature Flows #Geometry #Mathematical physics #Mathematics #Physics #Pure mathematics #Riemann curvature tensor #Scalar (mathematics) #Scalar curvature #hep-th
paper · pdf · doi:10.1088/0264-9381/22/13/017
published in Classical and Quantum Gravity 22(13), 2797-2809 (IOP Publishing) · 20 pages
arxiv created 2005/04/25 · openalex publication_date 2005/06/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Lovelock terms are polynomial scalar densities in the Riemann curvature tensor that have the remarkable property that their Euler-Lagrange derivatives contain derivatives of the metric of order not higher than two (while generic polynomial scalar densities lead to Euler-Lagrange derivatives with derivatives of the metric of order four). A characteristic feature of Lovelock terms is that their first nonvanishing term in the expansion of the metric around flat space is a total derivative. In this paper, we investigate generalized Lovelock terms defined as polynomial scalar densities in the Riemann curvature tensor and its covariant derivatives (of arbitrarily high but finite order) such that their first nonvanishing term in the expansion of the metric around flat space is a total derivative. This is done by reformulating the problem as a BRST cohomological one and by using cohomological tools. We determine all the generalized Lovelock terms. We find, in fact, that the class of nontrivial generalized Lovelock terms contains only the usual ones. Allowing covariant derivatives of the Riemann tensor does not lead to new structure. Our work provides a novel algebraic understanding of the Lovelock terms in the context of BRST cohomology.