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Recently we introduced mixed-state localization operators associated to a density operator and a (compact) domain in phase space. We continue the investigations of their eigenvalues and eigenvectors. Our main focus is the definition of a…

Functional Analysis · Mathematics 2018-08-21 Franz Luef , Eirik Skrettingland

Quantum harmonic analysis on phase space is shown to be linked with localization operators. The convolution between operators and the convolution between a function and an operator provide a conceptual framework for the theory of…

Functional Analysis · Mathematics 2017-10-17 Franz Luef , Eirik Skrettingland

This paper presents a proof of an uncertainty principle of Donoho-Stark type involving $\varepsilon$-concentration of localization operators. More general operators associated with time-frequency representations in the Cohen class are then…

Functional Analysis · Mathematics 2018-01-12 Paolo Boggiatto , Evanthia Carypis , Alessandro Oliaro

We investigate the $\tau$-quantizations and Cohen's class distributions of a suitable class of trace-class operators, called Feichtinger's operators, and show that it is a convenient substitute for the class of Schwartz operators. Many…

Functional Analysis · Mathematics 2023-01-13 Federico Bastianoni , Franz Luef

For the Weyl-Heisenberg group, convolutions between functions and operators were defined by Werner as a part of a framework called quantum harmonic analysis. We show how recent results by Feichtinger can be used to extend this definition to…

Functional Analysis · Mathematics 2024-10-11 Hans G. Feichtinger , Simon Halvdansson , Franz Luef

We introduce Quantum Time-Frequency Analysis, which expands the approach of Quantum Harmonic Analysis to include modulations of operators in addition to translations. This is done by a projective representation of double-phase space, and we…

Functional Analysis · Mathematics 2024-03-04 Franz Luef , Henry McNulty

Inspired by a recent article \cite[JFAA, 28(2):1-34, (2022)]{Skrettingland2022JoFAaA}, this paper is devoted to the study of suitable window class in the framework of bounded linear operators on $L^2(\rd)$. We establish a natural and…

Functional Analysis · Mathematics 2022-10-12 Weichao Guo , Guoping Zhao

Phase spaces as given by the Wigner distribution function provide a natural description of infinite-dimensional quantum systems. They are an important tool in quantum optics and have been widely applied in the context of time-frequency…

Quantum Physics · Physics 2023-10-27 Bálint Koczor , Frederik vom Ende , Maurice de Gosson , Steffen J. Glaser , Robert Zeier

The purpose of this Note is to study a simple class of mixed states and the corresponding density operators (matrices). These operators, which we call quite Toeplitz density operators correspond to states obtained from a fixed function…

Mathematical Physics · Physics 2019-07-05 Maurice de Gosson

Time-frequency analysis have played a crucial role in the development of localization operators in the last twenty years. We present its applications to the study of boundedness and Schatten Class property for such operators. In particular,…

Functional Analysis · Mathematics 2020-02-11 Elena Cordero

The Wigner Phase Operator (WPO) is identified as an operator valued measure (OVM) and its eigen states are obtained. An operator satisfying the canonical commutation relation with the Wigner phase operator is also constructed and this…

Quantum Physics · Physics 2013-12-24 T. Subeesh , Vivishek Sudhir

Phase operators are constructed using a Klauder-Berezin coherent state quantization in finite Hilbert subspaces of the Hilbert space of Fourier series. The study of infinite dimensional limits of mean values of some observables phase leads…

Quantum Physics · Physics 2016-08-16 Pedro L. García de León , Jean-Pierre Gazeau

We prove variants of Wiener's Tauberian theorem in the framework of quantum harmonic analysis, i.e. for convolutions between an absolutely integrable function and a trace class operator, or of two trace class operators. Our results include…

Functional Analysis · Mathematics 2020-12-18 Franz Luef , Eirik Skrettingland

Time-frequency localization operators, originally introduced by Daubechies (1988), provide a framework for localizing signals in the phase space and have become a central tool in time-frequency analysis. In this paper we introduce and study…

Functional Analysis · Mathematics 2025-11-04 Elena Cordero , Edoardo Pucci

In this note we exhibit recent advances in signal analysis via time-frequency distributions. New members of the Cohen class, generalizing the Wigner distribution, reveal to be effective in damping artefacts of some signals. We will survey…

Functional Analysis · Mathematics 2019-12-25 Elena Cordero , Maurice de Gosson , Monika Dörfler , Fabio Nicola

We establish a generalisation of the fundamental state convertibility theorem in quantum information to the context of bipartite quantum systems modelled by commuting semi-finite von Neumann algebras. Namely, we establish a generalisation…

Operator Algebras · Mathematics 2020-09-15 Jason Crann , David W. Kribs , Rupert H. Levene , Ivan G. Todorov

We find the position-momentum decomposition of the quantum operators of the classic Meixner random variables. The position-momentum decomposition involves translation operators, which are used to give a new characterization of the Meixner…

Probability · Mathematics 2024-04-23 Nobuaki Obata , Aurel I. Stan , Hiroaki Yoshida

In this paper, we describe the general framework to describe the diffusion operators associated to a positive matrix. We define the equations associated to diffusion operators and present some general properties of their state vectors. We…

Numerical Analysis · Mathematics 2012-06-19 Dohy Hong , Gérard Burnside

Toeplitz operators (also called localization operators) are a generalization of the well-known anti-Wick pseudodifferential operators studied by Berezin and Shubin. When a Toeplitz operator is positive semi-definite and has trace one we…

Quantum Physics · Physics 2022-10-19 Maurice de Gosson

Partial transpose is an important operation for quantifying the entanglement, here we study the (partial) transpose of any single (two-mode) operators. Using the Fock-basis expansion, it is found that the transposed operator of an arbitrary…

Quantum Physics · Physics 2021-07-07 Liyun Hu , Luping Zhang , Xiaoting Chen , Wei Ye , Qin Guo , Hongyi Fan
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