Boundaries are relevant in quantum field theory (QFT) and play a fundamental role in gravity, in particular regarding the physics of black holes and cosmology. The presence or absence of boundary degrees of freedom is especially important. We discuss here a simple linear model where classical boundary degrees of freedom are introduced from the start and study --by precisely constructing the Hamiltonian formulation and the Fock space quantization-- the relevant Hilbert spaces and important observables in the presence of boundaries. We will briefly discuss the physical implications of our model, both from the point of view of quantum mechanics and QFT.

Peer Reviewed