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By using a generalization of the optical tomography technique we describe the dynamics of a quantum system in terms of equations for a purely classical probability distribution which contains complete information about the system.

Quantum Physics · Physics 2009-10-30 S. Mancini , V. I. Man'ko , P. Tombesi

Introduced recently approach based on tomographic probability distribution of quantum states is shown to be closely related with the known notion of the quantum probability measures discussed in quantum information theory and positive…

Quantum Physics · Physics 2007-05-23 G. G. Amosov , V. I. Man'ko

Classical transport equations with probabilistic initial conditions can be viewed as quantum systems. In a discrete version they are probabilistic automata. The time-local probabilistic information is encoded in a classical wave function.…

Quantum Physics · Physics 2026-05-18 Christof Wetterich

We present graphical representation for genaralized quantum measurements (POVM). We represent POVM elements as Bloch vectors and find the conditions these vectors should satisfy in order to describe realizable physical measurements. We show…

Quantum Physics · Physics 2007-05-23 Pawel Kurzynski , Andrzej Grudka

Most methods for experimentally reconstructing the quantum state of light involve determining a quasiprobability distribution such as the Wigner function. In this paper we present a scheme for measuring individual density matrix elements in…

Quantum Physics · Physics 2009-11-07 K. L. Pregnell , D. T. Pegg

Forty-five years after the point de d\'epart [1] of density functional theory, its applications in chemistry and the study of electronic structures keep steadily growing. However, the precise form of the energy functional in terms of the…

Chemical Physics · Physics 2019-10-29 Philippe Blanchard , José M. Gracia-Bondía , Joseph C. Várilly

It is demonstrated that the nature of optical parametric amplification is a quantum phenomenon. The system Lagrangian can be constructed by the path integral of coherent state. The equations of motion for photon operators are indeed the…

Quantum Physics · Physics 2015-03-03 Fuyong Wang

With the ability to directly obtain the Wigner function and density matrix of photon states, quantum tomography (QT) has had a significant impact on quantum optics, quantum computing and quantum information. By an appropriate sequence of…

Liouville's theorem -- the preservation of phase-space volume -- is often presented as a corollary of Hamilton's canonical equations. Here we adopt an ensemble-first viewpoint in which the starting point is local probability conservation on…

Physics Education · Physics 2025-12-23 Enmanuel Rodríguez-Brea , Melvin Arias

We calculate exactly the quantum mechanical, temporal Wigner quasiprobability density for a single-mode, degenerate parametric amplifier for a system in the Gaussian state, viz., a displaced-squeezed thermal state. The Wigner function…

Quantum Physics · Physics 2021-03-16 Moorad Alexanian

The importance of the tomographic approach is that either in quantum mechanics as in classical mechanics the state of a physical system is expressed with the same family of functions, the tomograms. The extension of this procedure to…

General Relativity and Quantum Cosmology · Physics 2019-01-30 Cosimo Stornaiolo

In the Wigner-Moyal approach to quantum mechanics, we show that Moyal's starting point, the characteristic function $M(\tau,\theta)=\int \psi^{*}(x)e^{i(\tau {\hat p}+\theta{\hat x})}\psi(x)dx$, is essentially the primitive idempotent used…

Quantum Physics · Physics 2014-08-26 Basil J. Hiley

We consider a simple quantum system subjected to a classical random force. Under certain conditions it is shown that the noise-averaged Wigner function of the system follows an integro-differential stochastic Liouville equation. In the…

High Energy Physics - Theory · Physics 2008-02-03 Salman Habib

We explore whether quantum field theory can be understood as the statistical mechanics of a time-reversal-invariant stochastic generalization of Hamiltonian dynamics. The motivation for this project, started with this paper, is to assign…

Quantum Physics · Physics 2026-03-24 Simon Friederich , Mritunjay Tyagi

A method of representing probabilistic aspects of quantum systems is introduced by means of a density function on the space of pure quantum states. In particular, a maximum entropy argument allows us to obtain a natural density function…

Quantum Physics · Physics 2015-06-26 D. C. Brody , L. P. Hughston

We analyze the polymer representation of quantum mechanics within the deformation quantization formalism. In particular, we construct the Wigner function and the star-product for the polymer representation as a distributional limit of the…

General Relativity and Quantum Cosmology · Physics 2019-02-04 Jasel Berra-Montiel , Alberto Molgado

The Moyal--Weyl description of quantum mechanics provides a comprehensive phase space representation of dynamics. The Weyl symbol image of the Heisenberg picture evolution operator is regular in $\hbar$. Its semiclassical expansion…

High Energy Physics - Theory · Physics 2015-06-26 T. A. Osborn , F. H. Molzahn

The probability representation of quantum mechanics including propagators and tomograms of quantum states of the universe and its application to quantum gravity and cosmology are reviewed. The minisuperspaces modeled by oscillator, free…

General Relativity and Quantum Cosmology · Physics 2008-11-26 V. I. Man'ko , G. Marmoand C. Stornaiolo

We show how to represent the state and the evolution of a quantum computer (or any system with an $N$--dimensional Hilbert space) in phase space. For this purpose we use a discrete version of the Wigner function which, for arbitrary $N$, is…

Quantum Physics · Physics 2009-11-07 Pablo Bianucci , Cesar Miquel , Juan Pablo Paz , Marcos Saraceno

De Broglie and Bohm formulated a causal quantum mechanics with a phase space density whose integral over momentum reproduces the position probability density of usual statistical quantum theory. We propose a causal quantum theory with a…

High Energy Physics - Phenomenology · Physics 2015-06-25 S. M. Roy , V. Singh