Remigiusz Durka

Institute for Theoretical Physics, University of Wroclaw (Wroclaw, Poland)

Constrained BF theory as gravity

Abstract:
    In the late 70's MacDowell and Mansouri introduced a new formulation of gravity (with nice extension to N=1 supergravity) based on broken symmetry of the gauge theory. Recently this formalism was generalized to the form of the constrained topological BF theory of the anti-de Sitter (or de Sitter) gauge group.

    Presented framework provides the most general form of action for the first order gravity containing Einstein-Cartan action with negative (or positive) cosmological constant, Holst term and topological Euler, Pontryagin and Nieh-Yan invariants, and governed by only three constants (Newton constant, cosmological constant, and Immirzi parameter).

    From the black hole thermodynamics perspective such a construction is supported by differentiability of the action incorporated in the model, with the topological terms playing essential role in regularization of the gravitational Noether charges (mass, angular momentum, and entropy).