On the Space-Time and State-Space Geometries of Random Processes in Quantum Mechanics (original) (raw)

Quantum Brownian motion. II

1998

This paper is devoted to generalize some previous results presented in Gaioli et al., Int. J. Theor. Phys. 36, 2167 (1997). We evaluate the autocorrelation function of the stochastic acceleration and study the asymptotic evolution of the mean occupation number of a harmonic oscillator playing the role of a Brownian particle. We also analyze some deviations from the Bose population at low temperatures and compare it with the deviations from the exponential decay law of an unstable quantum system.

Quantum Brownian motion induced by an inhomogeneous tridimensional space and a S1 × R3 topological space-time

Journal of High Energy Physics

In this paper we investigate the Quantum Brownian motion of a point particle induced by quantum vacuum fluctuations of a massless scalar field in (3 + 1)-dimensional Minkowski spacetime with distinct conditions (Dirichlet, Neumann, mixed and quasiperiodic). The modes of the field are confined and compactified to a finite length region, which consequently provides a natural measure scale for the system. Useful expressions for the Wightman function have been obtained, which allow us to calculate analytical expressions for the velocity dispersion in all condition cases considered. We also obtain expressions for the velocity dispersion in the short and late time regimes. Finally, we exhibit some graphs in order to show the behavior of the velocity dispersions, discussing important divergencies that are present in our results.

Randomness in quantum mechanics: philosophy, physics and technology

Reports on progress in physics. Physical Society (Great Britain), 2017

This progress report covers recent developments in the area of quantum randomness, which is an extraordinarily interdisciplinary area that belongs not only to physics, but also to philosophy, mathematics, computer science, and technology. For this reason the article contains three parts that will be essentially devoted to different aspects of quantum randomness, and even directed, although not restricted, to various audiences: a philosophical part, a physical part, and a technological part. For these reasons the article is written on an elementary level, combining simple and non-technical descriptions with a concise review of more advanced results. In this way readers of various provenances will be able to gain while reading the article.

Stochastic Isometries in Quantum Mechanics

1999

The class of stochastic maps, that is, linear, trace-preserving, positive maps between the self-adjoint trace class operators of complex separable Hilbert spaces plays an important role in the representation of reversible dynamics and symmetry transformations. Here a characterization of the isometric stochastic maps is given and possible physical applications are indicated.