Entropy in Poincare gauge theory: Hamiltonian approach

The canonical generator G of local symmetries in Poincare gauge theory is constructed as an integral over a spatial section Sigma of spacetime. Its regularity (differentiability) on the phase space is ensured by adding a suitable surface term, an integral over the boundary of Sigma at infinity, which represents the asymptotic canonical charge. For black hole solutions, Sigma has two boundaries, one at infinity and the other at horizon. It is shown that the canonical charge at horizon defines entropy, whereas the regularity of G implies the first law of black hole thermodynamics.