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Quantum information processing and computing tasks can be understood as quantum networks, comprising quantum states and channels and possible physical transformations on them. It is hence pertinent to estimate the change in informational…

Quantum Physics · Physics 2026-03-17 Sohail , Vivek Pandey , Uttam Singh , Siddhartha Das

A generalization of the Gibbs-von Neumann relative entropy is proposed based on the quantum BBGKY [Bogolyubov-Born-Green-Kirkwood-Yvon] hierarchy as the nonequilibrium entropy for an N-body system. By using a generalization of the…

Statistical Mechanics · Physics 2007-05-23 A. Perez-Madrid

For a quantum state undergoing unitary Schr\"odinger time evolution, the von Neumann entropy is constant. Yet the second law of thermodynamics, and our experience, show that entropy increases with time. Ingarden introduced the quantum…

Quantum Physics · Physics 2019-07-03 Craig S. Lent

Many trace inequalities can be expressed either as concavity/convexity theorems or as monotonicity theorems. A classic example is the joint convexity of the quantum relative entropy which is equivalent to the Data Processing Inequality. The…

Functional Analysis · Mathematics 2022-10-25 Eric A. Carlen , Haonan Zhang

Entropy measures quantify the amount of information and correlation present in a quantum system. In practice, when the quantum state is unknown and only copies thereof are available, one must resort to the estimation of such entropy…

Quantum Physics · Physics 2024-03-27 Ziv Goldfeld , Dhrumil Patel , Sreejith Sreekumar , Mark M. Wilde

We define a quantum entropy conditioned on post-selection which has the von Neumann entropy of pure states as a special case. This conditional entropy can take negative values which is consistent with part of a quantum system containing…

Quantum Physics · Physics 2014-09-05 Sina Salek , Roman Schubert , Karoline Wiesner

We introduce the von Neumann entropy regularization of Unbalanced Non-commutative Optimal Transport, specifically Non-commutative Optimal Transport between semi-definite positive matrices (not necessarily with trace one). We prove the…

Optimization and Control · Mathematics 2024-02-28 Augusto Gerolin , Nataliia Monina

We study the interconversion of families of quantum states ("statistical experiments") via positive, trace-preserving (PTP) maps and clarify its mathematical structure in terms of minimal sufficient Jordan algebras, which can be seen to…

Quantum Physics · Physics 2026-05-15 Lauritz van Luijk , Henrik Wilming

The von Neumann entanglement entropy is a useful measure to characterize a quantum phase transition. We investigate the non-analyticity of this entropy at disorder-dominated quantum phase transitions in non-interacting electronic systems.…

Mesoscale and Nanoscale Physics · Physics 2008-01-27 X. Jia , A. R. Subramaniam , I. A. Gruzberg , S. Chakravarty

Changes of some unitarily invariant norms and anti-norms under the operation of partial trace are examined. The norms considered form a two-parametric family, including both the Ky Fan and Schatten norms as particular cases. The obtained…

Quantum Physics · Physics 2012-11-02 Alexey E. Rastegin

Quantum properties of the state associated to the gluon Green's function in the BFKL approach are studied using a discretization in virtuality space. Considering the coupling constant as imaginary, its density matrix corresponds to a pure…

High Energy Physics - Theory · Physics 2023-12-29 G. Chachamis , M. Hentschinski , A. Sabio Vera

We give an explicit characterisation of the quantum states which saturate the strong subadditivity inequality for the von Neumann entropy. By combining a result of Petz characterising the equality case for the monotonicity of relative…

Quantum Physics · Physics 2007-05-23 Patrick Hayden , Richard Jozsa , Denes Petz , Andreas Winter

Conditional von Neumann entropy is an intriguing concept in quantum information theory. In the present work, we examine the effect of global unitary operations on the conditional entropy of the system. We start with the set containing…

Quantum Physics · Physics 2018-06-01 Subhasree Patro , Indranil Chakrabarty , Nirman Ganguly

We present a bouquet of continuity bounds for quantum entropies, falling broadly into two classes: First, a tight analysis of the Alicki-Fannes continuity bounds for the conditional von Neumann entropy, reaching almost the best possible…

Quantum Physics · Physics 2016-09-06 Andreas Winter

Violation of Bell inequalities in bipartite systems represented by mutually-commuting von Neumann algebras has pioneered the study of vacuum entanglement in algebraic quantum field theory. It is unexpected that the maximal violation of Bell…

Functional Analysis · Mathematics 2026-04-16 Bingke Zheng , Shuyuan Yang , Jinchuan Hou , Kan He

We study quantum bipartite systems in a random pure state, where von Neumann entropy is considered as a measure of the entanglement. Expressions of the first and second exact cumulants of von Neumann entropy, relevant respectively to the…

Information Theory · Computer Science 2020-02-13 Lu Wei

This paper introduces a method for calculating the quantum relative entropy of channels, an essential quantity in quantum channel discrimination and resource theories of quantum channels. By building on recent developments in the…

Quantum Physics · Physics 2026-04-16 Gereon Koßmann , Mark M. Wilde

Information theory provides a framework for answering fundamental questions about the optimal performance of many important quantum communication and computational tasks. In many cases, the optimal rates of these tasks can be expressed in…

Quantum Physics · Physics 2024-12-25 Joshua Levin , Ariel Shlosberg , Vikesh Siddhu , Graeme Smith

We introduce a generalized Wigner-Yanase skew information and then derive the trace inequality related to the uncertainty relation. This inequality is a non-trivial generalization of the uncertainty relation derived by S.Luo for the quantum…

Quantum Physics · Physics 2010-01-10 S. Furuichi , K. Yanagi , K. Kuriyama

The paper presents variational formulae for entropy-like functionals, including Segal and R\'enyi entropies, for normal states on semifinite von Neumann algebras. The considered functionals are of the form $\tau(f(h))$ where $\tau$ is a…

Operator Algebras · Mathematics 2025-10-10 Andrzej Łuczak , Hanna Podsędkowska , Rafał Wieczorek