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In this paper, we prove a non-commutative version of the Weyl-von Neumann theorem for representations of unital, separable AH algebras into countably decomposable, semifinite, properly infinite, von Neumann factors, where an AH algebra…

Operator Algebras · Mathematics 2019-11-19 Junhao Shen , Rui Shi

We propose replacing the instantaneous state reduction in von Neumann selective measurement with continuous nonlinear evolution. Despite its nonlinearity, this evolution preserves the equivalence of quantum ensembles and hence obeys the…

Quantum Physics · Physics 2026-05-19 Jakub Rembieliński , Karol Ławniczak

We propose a theory of quantum (statistical) measurement which is close, in spirit, to Hepp's theory, which is centered on the concepts of decoherence and macroscopic (classical) observables, and apply it to a model of the Stern-Gerlach…

Mathematical Physics · Physics 2023-03-01 Walter F. Wreszinski

A probability-measure-preserving transformation has the Weak Pinsker Property (WPP) if for every $\epsilon>0$ it is measurably conjugate to the direct product of a transformation with entropy $<\epsilon$ and a Bernoulli shift. In a recent…

Dynamical Systems · Mathematics 2021-02-11 Lewis Bowen

Quantum information theory explores numerous properties that surpass classical paradigms, offering novel applications and benefits. Among these properties, negative conditional von Neumann entropy (CVNE) is particularly significant in…

Quantum Physics · Physics 2024-11-22 Jan Horodecki , Piotr Mironowicz

We establish a general framework to study the rate of convergence of a Euler type approximation scheme with decreasing time steps to the invariant measure, for a general class of stochastic systems. The error is measured in general…

Probability · Mathematics 2026-03-03 Aurélien Alfonsi , Vlad Bally , Arturo Kohatsu-Higa

We denote by C_p(X,G) the group of all continuous functions from a space X to a topological group G endowed with the topology of pointwise convergence. We say that spaces X and Y are G-equivalent provided that the topological groups…

General Topology · Mathematics 2010-04-26 Dmitri Shakhmatov , Jan Spěvák

We give a detailed proof of a new characterization of the Weak Expectation Property (WEP) announced by Haagerup in the 1990's but unavailable (in any form) till now. Our main result is motivated by a well known conjecture of Kirchberg,…

Operator Algebras · Mathematics 2019-07-24 Gilles Pisier

Let $n\geq 2$ and $G_n=\mathbb{Z}^n\rtimes SL_n(\mathbb{Z})$. We classify all $G_n$-invariant von Neumann subalgebras in $L(G_n)$. For $n=2$, this gives an alternative proof of the previous result of Jiang-Liu. For $n\geq 3$, this gives the…

Operator Algebras · Mathematics 2026-01-13 Yongle Jiang , Hongyi Li

J. v. Neumann justified the collapse postulate by the empirical fact of the repeatability of a measurement at a single quantum system. However, in his quantum mechanical treatment of the measurement process repeatability emerges without…

Quantum Physics · Physics 2013-11-06 Michael Zirpel

If $H$ is a lattice in a locally compact second countable group $G$, then we show that $G$ has property A (respectively is coarsely embeddable into Hilbert space) if and only if $H$ has property A (respectively is coarsely embeddable into…

Operator Algebras · Mathematics 2014-03-28 Steven Deprez , Kang Li

We generalize the notion of an approximate indicator for a closed subgroup $H$ of a locally compact group $G$ introduced by Aristov, Runde, and Spronk and extend their characterization of the existence of such nets in terms of the…

Functional Analysis · Mathematics 2015-06-10 Zsolt Tanko

As is well known, the equivalence between amenability of a locally compact group $G$ and injectivity of its von Neumann algebra $\mathcal{L}(G)$ does not hold in general beyond inner amenable groups. In this paper, we show that the…

Operator Algebras · Mathematics 2014-11-04 Jason Crann , Matthias Neufang

We prove a "quantified" version of the Weyl-von Neumann theorem, more precisely, we estimate the ranks of approximants to compact operators appearing in the Voiculescu's theorem applied to commutative algebras. This allows considerable…

Functional Analysis · Mathematics 2010-05-24 Jan Spakula

Lenz and Stollmann recently proved the existence of the integrated density of states in the sense of uniform convergence of the distributions for certain operators with aperiodic order. The goal of this paper is to establish a relation…

Mathematical Physics · Physics 2007-05-23 Gabor Elek

We prove, among other results, that three standard measures of weak non-compactness coincide in preduals of JBW$^*$-triples. This result is new even for preduals of von Neumann algebras. We further provide a characterization of…

Operator Algebras · Mathematics 2019-11-14 Jan Hamhalter , Ondřej F. K. Kalenda , Antonio M. Peralta , Hermann Pfitzner

A triple of finite von Neumann algebras $B\subseteq N\subseteq M$ is said to have the relative weak asymptotic homomorphism property if there exists a net of unitary operators $\{u_{\lambda}\}_{\lambda\in \Lambda}$ in $B$ such that…

Operator Algebras · Mathematics 2010-05-19 Junsheng Fang , Mingchu Gao , Roger R. Smith

A state $\rho=(\rho_n)_{n=1}^{\infty}$ is a sequence such that $\rho_n$ is a density matrix on $n$ qubits. It formalizes the notion of an infinite sequence of qubits. The von Neumann entropy $H(d)$ of a density matrix $d$ is the Shannon…

Quantum Physics · Physics 2025-04-15 Tejas Bhojraj

This paper addresses a conjecture of Kadison and Kastler that a von Neumann algebra M on a Hilbert space H should be unitarily equivalent to each sufficiently close von Neumann algebra N and, moreover, the implementing unitary can be chosen…

Operator Algebras · Mathematics 2013-07-30 Jan Cameron , Erik Christensen , Allan M. Sinclair , Roger R. Smith , Stuart White , Alan D. Wiggins

Weak equivalence principle (WEP) is one of the cornerstones of the modern theories of gravity, stating that the trajectory of a freely falling test body is independent of its internal structure and composition. Even though WEP is known to…

High Energy Physics - Phenomenology · Physics 2016-08-30 Tigran Kalaydzhyan