Mecânica quântica não-aditiva

João Philipe Macedo Braga

Published Jan 1, 2015• 0 citations

Abstract

In this thesis, we study the nonadditive quantum mechanics (NAQM), which is a theory developed from first principles in order to understand the effects of the space metric in the quantum theory. In non-Euclidean spaces, the translation of length ∆x does not necessarily take a particle from the position x to x + ∆x. The result of this translation depends on the metric. This is the starting point for the development of the NAQM. Through a redefinition of the translation operator, we obtain new commutation relations between the position operator and the momentum operator, and a Schrödinger-like equation which describes the time evolution of the state of a particle. We show that this equation, with appropriate boundary conditions, can be seen as a Sturm-Liouville problem, ensuring that the energies of the particle are real and that the eigenstates of the hamiltonian are orthonormal and form a basis in the space of the states. In spite of these modifications, we show the determinism in the time evolution, the superposition principle and the local and global probability conservation remain valid. On the other hand, we generalize the Ehrenfest theorem, showing that, for the average values of the physical quantities, the NAQM is identical to the classical mechanics in a non-inertial reference frame, and we demonstrate the existence of a nonzero minimum uncertainty for the momentum. Besides, we investigate, classically as well as quantically, the dynamical effects of the metric in the time evolution of a free particle. In order to perform the quantum simulation, we adapt the split operator technique to solve numerically the new Schrödinger equation. Lastly, we explore the possibility of mapping of several physical problems of different nature through the arising of an effective potential which appears due to a simple change of coordinates.

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