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The Wigner function was introduced as an attempt to describe quantum-mechanical fields with the tools inherited from classical statistical mechanics. In particular, it is widely used to describe the properties of radiation fields. In fact,…

Quantum Physics · Physics 2025-04-10 Juan Camilo López Carreño

The Euclidean formulation of quantum gravity can be interpreted in terms of a probability distribution over Riemannian manifolds. In the context of de Sitter gravity, the statistics of the total volume according to this distribution is…

High Energy Physics - Theory · Physics 2026-05-07 David Blanco , Guillem Pérez-Nadal , Bruno Sivilotti

According to a classical result due to Hudson, the Wigner function of a pure, continuous variable quantum state is non-negative if and only if the state is Gaussian. We have proven an analogous statement for finite-dimensional quantum…

Quantum Physics · Physics 2007-05-23 David Gross

We analyse the dynamics of expectation values of quantum observables for the time-dependent semiclassical Schr\"odinger equation. To benefit from the positivity of Husimi functions, we switch between observables obtained from Weyl and…

Numerical Analysis · Mathematics 2013-03-19 Johannes Keller , Caroline Lasser

A new definition of the Wigner function for quantum fields coupled to curved space--time and an external Yang--Mills field is studied on the example of a scalar and a Dirac fields. The definition uses the formalism of the tangent bundles…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Oleg A. Fonarev

The mixed density operator for coarsegrained eigenlevels of a static Hamiltonian is represented in phase space by the spectral Wigner function, which has its peak on the corresponding classical energy shell. The action of trajectory…

Quantum Physics · Physics 2024-03-05 Alfredo M. Ozorio de Almeida

A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum state tomography. We theoretically propose and experimentally…

The mathematical structure of the temporal gauge of QED is critically examined in both the alternative formulations characterized by either positivity or regularity of the Weyl algebra. The conflict between time translation invariance and…

Mathematical Physics · Physics 2009-11-07 J. Loeffelholz , G. Morchio , F. Strocchi

Representations of quantum state vectors by complex phase space amplitudes, complementing the description of the density operator by the Wigner function, have been defined by applying the Weyl-Wigner transform to dyadic operators, linear in…

Quantum Physics · Physics 2015-05-19 A. J. Bracken , P. Watson

In quantum optics, the quantum state of a light beam is represented through the Wigner function, a density on $\mathbb R^2$ which may take negative values but must respect intrinsic positivity constraints imposed by quantum physics. In the…

Statistics Theory · Mathematics 2015-06-24 Karim Lounici , Katia Meziani , Gabriel Peyré

Quantum theory is the focus of current research. Likelihood functions are widely used in many fields. Because the classic likelihood functions are too strict for extreme data in practical applications, Yager proposed soft ordered weighted…

Quantum Physics · Physics 2021-09-02 Tianxiang Zhan , Yuanpeng He , Fuyuan Xiao

Over decades, the time evolution of Wigner functions along classical Hamiltonian flows has been used for approximating key signatures of molecular quantum systems. Such approximations are for example the Wigner phase space method, the…

Numerical Analysis · Mathematics 2014-11-11 Wolfgang Gaim , Caroline Lasser

It has recently been shown that it is possible to represent the complete quantum state of any system as a phase-space quasi-probability distribution (Wigner function) [Phys Rev Lett 117, 180401]. Such functions take the form of expectation…

Quantum Physics · Physics 2017-08-16 R. P. Rundle , P. W. Mills , Todd Tilma , J. H. Samson , M. J. Everitt

For an ergodic action of the group $Z^n$ on a probability space and a given arbitrarily slowly decreasing to zero sequence, there exists an integrable function such that the standard ergodic time averages for it converge almost everywhere…

Dynamical Systems · Mathematics 2025-08-04 Valery V. Ryzhikov

We propose a Wigner quasiprobability distribution function for Hamiltonian systems in spaces of constant curvature --in this paper on hyperboloids--, which returns the correct marginals and has the covariance of the Shapiro functions under…

Quantum Physics · Physics 2015-06-26 Miguel Angel Alonso , George S. Pogosyan , Kurt Bernardo Wolf

We consider in what sense quantum tunnelling is associated with non-classical probabilistic behaviour. We use the Wigner function quasi-probability description of quantum states. We give a definition of tunnelling that allows us to say…

Quantum Physics · Physics 2021-01-04 Yin Long Lin , Oscar C. O. Dahlsten

The coherence properties of the classical waves are discussed in terms of the Cauchy problem for the wave equation, and of a discrete representation by an ensemble of Hamiltonian systems. Wave quanta are related to specific "action fields",…

Quantum Physics · Physics 2021-09-15 M. Grigorescu

The Wigner crystal, an ordered array of electrons, is one of the very first proposed many-body phases stabilized by the electron-electron interaction. This electron solid phase has been reported in ultra-clean two-dimensional electron…

Mesoscale and Nanoscale Physics · Physics 2023-06-28 Lili Zhao , Wenlu Lin , Yoon Jang Chung , Adbhut Gupta , Kirk W. Baldwin , Loren N. Pfeiffer , Yang Liu

We introduce a new density for the representation of quantum states on phase space. It is constructed as a weighted difference of two smooth probability densities using the Husimi function and first-order Hermite spectrograms. In contrast…

Mathematical Physics · Physics 2016-03-07 Johannes Keller , Caroline Lasser , Tomoki Ohsawa

In this paper we generalize the concept of Wigner function in the case of quantum mechanics with a minimum length scale arising due to the application of a generalized uncertainty principle (GUP). We present the phase space formulation of…

High Energy Physics - Theory · Physics 2021-01-28 Prathamesh Yeole , Vipul Kumar , Kaushik Bhattacharya