Mercoledi' 4 giugno, alle 16.00, presso l' aula seminari il Porf. Kijowski terrĂ  un seminario dal titolo:

On the canonical structure of General Relativity
 Abstract: Hamiltonian evolution of gravitational field within a spatially compact world tube with non-vanishing boundary is discussed. A universal Hamiltonian identity is proved which relates gravitational  Cauchy data (internal and external 3-geometry of a Cauchy surface) with boundary data (internal and external 3-geometry of the tube).
It is shown how different ways to control the boundary data lead to different quasi-local definitions of gravitational energy (mass).