ON THE RELATION BETWEEN QUADRATIC AND LINEAR CURVATURE LAGRANGIANS IN POINCARE GAUGE GRAVITY

摘要

We discuss the choice of the Lagrangian in the Poincare gauge theory of gravity. Drawing analogies to earlier de Sitter gauge models, we point out the possibility of deriving the Einstein-Cartan Lagrangian without cosmological term from a modified quadratic curvature invariant of topological type.