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Related papers: Projection operator formalism and entropy

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Traditional measures of entropy, like the Von Neumann entropy, while fundamental in quantum information theory, are insufficient when interpreted as thermodynamic entropy due to their invariance under unitary transformations, which…

Quantum Physics · Physics 2025-05-20 Shivam Sinha , Nripendra Majumbdar , S. Aravinda

The realization of Hawking radiation in optical analogs has historically focused on kinematic observables, such as the effective temperature determined by the horizon's surface gravity. A complete thermodynamic description, however,…

Optics · Physics 2026-05-26 Hasan Oguz

A microscopic understanding of the thermodynamic entropy in quantum systems has been a mystery ever since the invention of quantum mechanics. In classical physics, this entropy is believed to be the logarithm of the volume of phase space…

Quantum Physics · Physics 2013-05-08 J. M. Deutsch , Haibin Li , Auditya Sharma

Unlike standard quantum mechanics, dynamical reduction models assign no particular a priori status to `measurement processes', `apparata', and `observables', nor self-adjoint operators and positive operator valued measures enter the…

Quantum Physics · Physics 2009-11-13 A. Bassi , G. C. Ghirardi , D. G. M. Salvetti

Thermodynamic uncertainty relations quantifying a trade-off between current fluctuation and entropy production have been found in various stochastic systems. Herein, we study the thermodynamic uncertainty relations for Langevin systems…

Statistical Mechanics · Physics 2020-01-22 Tan Van Vu , Yoshihiko Hasegawa

We develop a non-extensive thermodynamic formalism for the one-sided shift on a finite alphabet, inspired by Tsallis' generalization of Boltzmann entropy in statistical physics. We introduce notions of $q$-entropy, $q$-pressure, and…

Dynamical Systems · Mathematics 2026-03-11 Artur O. Lopes , Paulo Varandas

Given the algebra of observables of a quantum system subject to selection rules, a state can be represented by different density matrices. As a result, different von Neumann entropies can be associated with the same state. Motivated by a…

Quantum Physics · Physics 2021-05-25 Paolo Facchi , Giovanni Gramegna , Arturo Konderak

The second law of thermodynamics states that entropy increases (or does not change) by time in an isolated system. As microscopic physical laws are reversible, the origin of irreversibility is not straightforward. Although the outcome of a…

Statistical Mechanics · Physics 2013-02-19 Balint Szabo

We present a microscopic derivation of the laws of continuum mechanics of nonideal ordered solids including dissipation, defect diffusion, and heat transport. Starting point is the classical many-body Hamiltonian. The approach relies on the…

Statistical Mechanics · Physics 2022-11-23 Florian Miserez , Saswati Ganguly , Rudolf Haussmann , Matthias Fuchs

For a dynamical system far from equilibrium, one has to deal with empirical probabilities defined through time-averages, and the main problem is then how to formulate an appropriate statistical thermodynamics. The common answer is that the…

Statistical Mechanics · Physics 2009-11-10 A. Carati

Here we deconstruct, and then in a reasoned way reconstruct, the concept of "entropy of a system," paying particular attention to where the randomness may be coming from. We start with the core concept of entropy as a COUNT associated with…

General Physics · Physics 2017-05-10 Tommaso Toffoli

In quantum gravity, it has been argued that a proper accounting of the role played by an observer promotes the von Neumann algebra of observables in a given spacetime subregion from Type III to Type II. While this allows for a…

High Energy Physics - Theory · Physics 2025-07-17 Julian De Vuyst , Stefan Eccles , Philipp A. Hoehn , Josh Kirklin

Some general considerations on the notion of entropy in physics are presented. An attempt is made to clarify the question of the differentiation between physical entropy (the Clausius-Boltzmann one) and quantities called entropies…

Statistical Mechanics · Physics 2007-05-23 Roberto Luzzi , Áurea R. Vasconcellos , J. Galvão Ramos

It exists a large class of systems for which the traditional notion of extensivity breaks down. From experimental examples we induce two general hypothesis concerning such systems. In the first the existence of an internal coordinate system…

Statistical Mechanics · Physics 2015-03-09 J-P. Badiali , A. El Kaabouchi

Despite its enormous empirical success, the formalism of quantum theory still raises fundamental questions: why is nature described in terms of complex Hilbert spaces, and what modifications of it could we reasonably expect to find in some…

Quantum Physics · Physics 2017-04-27 Marius Krumm , Howard Barnum , Jonathan Barrett , Markus P. Mueller

This paper investigates the relationship between categorical entropy and von Neumann entropy of quantum lattices. We begin by studying the von Neumann entropy, proving that the average von Neumann entropy per site converges to the logarithm…

Statistical Mechanics · Physics 2025-05-27 Haiqi Wu , Kai Xu

In ordinary Boltzmann-Gibbs thermostatistics, the relative entropy expression plays the role of generalized free energy, providing the difference between the off-equilibrium and equilibrium free energy terms associated with Boltzmann-Gibbs…

Statistical Mechanics · Physics 2007-12-13 G. B. Bagci

A renormalized version of the von Neumann quantum entropy (which is finite and continuous in general, infinite dimensional case) and which obeys several of the natural physical demands (as expected for a "good" measure of entanglement in…

Quantum Physics · Physics 2022-11-11 Roman Gielerak

A mathematical interpretation of the usual definition of entropy (for a discrete probability distribution or a trace 1 positive operator) is given. This formulation makes some properties of entropy immediate.

General Mathematics · Mathematics 2007-05-23 Eliahu Levy

We use the relative modular operator to define a generalized relative entropy for any convex operator function g on the positive real line satisfying g(1) = 0. We show that these convex operator functions can be partitioned into convex…

Mathematical Physics · Physics 2015-06-26 Andrew Lesniewski , Mary Beth Ruskai