Talk detail

Participant	Naddeo, Adele
Institution	INFN, Sezione di Napoli - Complesso Universitario Monte S. Angelo, Via Cinthia - Napoli - - Italy

Session	EU2B	Accepted		Order	Time
Talk	Oral abstract	Title	Gravitational entropy production in a quantum low-energy gravity model free from causality violation problems
Coauthors
Abstract	Wave function collapse following a measurement process is a controversial issue of quantum physics. It introduces an element of strong nonlinearity and irreversibility in an otherwise unitary and reversible dynamics. Several proposals of modification of Quantum Mechanics have been put forward, which considered the possible role of gravity in the wave function collapse as a result of the incompatibility of general relativity and quantum unitary time evolution. Here we present a nonunitary model of Newtonian Gravity, which shows several appealing features. We show the results of numerical simulations of a system of two particles in a harmonic trap interacting via delta-like and gravitational interactions. Starting from an energy eigenstate, we find that energy expectation remains constant but a slow net variation of the von Neumann entropy for the whole system takes place, with a small modulation induced on the entanglement entropy of the two particles. Finally, we show how a one-parameter generalization of the model, reproducing the nonlinear Newton-Schroedinger equation as the parameter goes to infinity, is free from any causality-violation problem for any finite value of it.
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