Palatini Gauss-Bonnet theory

par Prof. Marc Henneaux (Université Libre de Bruxelles, Collège de France)

jeudi 19 févr. 2026, 13:30 → 14:30 Europe/Paris

Salle 1180, bâtiment E2 (Salle des séminaires )

A class of models in even spacetime dimensions 2n is considered.  These share many similarities with Chern-Simons theories in odd spacetime dimensions 2n+1.  The independent dynamical variables of these models are a GL(2n)-connection and a metric in internal space. The action is a polynomial of degree n in the curvature of the connection, with indices saturated by means of the metric and the Levi-Civita tensor.  The cases of 2 and 4 spacetime dimensions are treated in detail.  In 2 dimensions, the theory reduces to a boundary theory in 1+0 dimensions and is equivalent to a particle moving in 3-dimensional anti-de Sitter space when formulated on the interval. The dynamics is more intricate in higher dimensions (n>1), where local degrees of freedom are present.