Quantum Stochastics

Ramabhadra Vasudevan, Kanniyappan Parthasarathy, Ravishankar Ramanathan

Preface / Forward / Acknowledgements / Introduction / Invitation to Stochastic Calculus / Hydrodynamical Formulation of Quantum Mechanics / Stochastic Diffusion Processes / Selected Problems in Stochastic Mechanics / Stochastic Variational Principles / Euclidean Quantum Mechanics / Stochastic Path Space Picture / Relativistic Stochastic Mechanics / Dirac Equation - Stochastic Viewpoint / Stochastic Field Theory / Stochastic Mechanics on Manifolds / Stochastic Route to Quantum Mechanics - Quest Continues / References / Author Index / Subject Index.

Günter Mahler A, Volker A. Weberruß

Stanley Gudder

Ying Oon Tan

Previously [2004, AIP Conf. Proc., 750, 361], we considered a stochastic mechanics in the form of a stochastic differential equation mdxdt = μ(t) where μ(t) is a stochastic process defined by the set of Bohmian momentum time histories from an ensemble of particles. In this paper, we consider another stochastic differential equation d2xdt2 = 1m[−dV(x)dx + ζ(t)] where the stochastic force ζ(t) is a stochastic process defined by the set of quantum force time histories from an ensemble of particles. We show that, if the stochastic process is a purely random process characterized by an n‐th order joint probability density in the form of products of delta functions, then the stochastic mechanics with the stochastic force ζ(t) is equivalent to quantum mechanics in the sense that the former yields the same position probability density as the latter. However, for a particular non‐purely random process, we show that the stochastic mechanics with the stochastic force ζ(t) is not equivalent to quantum mechanics. Therefore, this stochastic mechanics is also generally not equivalent to quantum mechanics.

Un Cig Ji, Kalyan B. Sinha

We first study a class of fundamental quantum stochastic processes induced by the generators of a six dimensional non-solvable Lie †-algebra consisting of all linear combinations of the generalized Gross Laplacian and its adjoint, annihilation operator, creation operator, conservation, and time, and then we study the quantum stochastic integrals associated with the class of fundamental quantum stochastic processes, and the quantum Itô formula is revisited. The existence and uniqueness of solution of a quantum stochastic differential equation is proved. The unitarity conditions of solutions of quantum stochastic differential equations associated with the fundamental processes are examined. The quantum stochastic calculus extends the Hudson-Parthasarathy quantum stochastic calculus.

Stanley Gudder