We exploit the separation of the filtering and control aspects of quantum feedback control to consider the optimal control as a classical stochastic problem on the space of quantum states. We derive the corresponding Hamilton-Jacobi-Bellman equations using the elementary arguments of classical control theory and show that this is equivalent, in the Stratonovich calculus, to a stochastic Hamilto...

We present a class of classically marginal N-vector models in d=4 and d=3 whose scalar potentials can be written as subdeterminants of symmetric matrices. The d=3 case can be thought of as a generalization of the scalar sector of the Bagger-Lambert-Gustavsson model. Using the Hubbard-Stratonovich transformation we calculate their effective potentials which exhibit intriguing large-N scaling beh...

The paper mainly investigates a stochastic SIRS epidemic model with Logistic birth and nonlinear incidence. We obtain new threshold value (R0m) through the Stratonovich differential equation, different from usual basic reproduction number. If R0m<1, disease-free equilibrium of illness is globally asymptotically stable in probability one. R0m>1, disease permanent mean one has an endemic st...

We propose a quantum-classical hybrid scheme for implementing the nonunitary Gutzwiller factor using discrete Hubbard-Stratonovich transformation, which allows us to express as linear combination of unitary operators involving only single-qubit rotations, at cost sum over auxiliary fields. To perform fields, we introduce two approaches that have complementary features. The first approach employ...

Calculus via regularizations and rough paths are two methods to approach stochastic integration calculus close pathwise calculus. The origin of theory is purely deterministic, regularization based on deterministic techniques but there still a probability in the background. goal this paper establish connection between stochastically controlled-type processes, concept reminiscent from theory, so-...