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Related papers: Density Matrix Realism

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According to quantum theory, pure physical states correspond to equivalence classes of state vectors, where any two members of one class differ by a complex factor. The point is that such a factor does not change the probability for the…

Quantum Physics · Physics 2017-11-06 Ulrich Mutze

It has been experimentally demonstrated that quantum coherence can persist in macroscopic phenomena [J.R. Friedman et al.,Nature, 406 (2000) 43]. To face the challenge of this new fact, in this article QM in its standard form is assumed to…

Quantum Physics · Physics 2007-05-23 F. Herbut

Although quantum mechanics is one of our most successful physical theories, there has been a long-standing debate about the interpretation of the wave function---the central object of the theory. Two prominent views are that (i) it…

Quantum Physics · Physics 2012-04-16 Roger Colbeck , Renato Renner

Effect of replacing the classical game object with a quantum object is analyzed. We find this replacement requires a throughout reformation of the framework of Game Theory. If we use density matrix to represent strategy state of players,…

Quantum Physics · Physics 2007-05-23 Jinshan Wu

We discuss the concept of how entanglement changes with respect to different factorizations of the total algebra which describes the quantum states. Depending on the considered factorization a quantum state appears either entangled or…

Quantum Physics · Physics 2011-11-15 Walter Thirring , Reinhold A. Bertlmann , Philipp Köhler , Heide Narnhofer

In a paper of us, it is showed that Density Matrices do not provide a complete description of ensembles of states in quantum mechanics, since they lack measurable information concerning the preparation of the ensembles. Bodor and Di\'osi…

Quantum Physics · Physics 2012-04-06 F. Fratini , A. G. Hayrapetyan

The density matrix is a positive semidefinite operator of trace 1 characterizing the state of a quantum system. We consider the inverse problem to reconstruct such density matrices from indirect measurements, also known as quantum state…

Numerical Analysis · Mathematics 2026-03-06 Florian Oberender , Thorsten Hohage

A hypothetical formulation of quantum mechanics is presented so as to reconcile it with macro-realism. On the analogy drawn from thermodynamics, an objective description of wave packet reduction is postulated, in which a characteristic…

Quantum Physics · Physics 2007-05-23 Takuya Okabe

We introduce a formulation of quantum theory (QT) as a general probabilistic theory but expressed via quasi-expectation operators (QEOs). This formulation provides a direct interpretation of density matrices as quasi-moment matrices. Using…

Quantum Physics · Physics 2022-03-10 Alessio Benavoli , Alessandro Facchini , Marco Zaffalon

The predictions that quantum theory makes about the outcomes of measurements are generally probabilistic. This has raised the question whether quantum theory can be considered complete, or whether there could exist alternative theories that…

Quantum Physics · Physics 2016-04-13 Roger Colbeck , Renato Renner

Dualities in physics have challenged traditional forms of scientific realism by undermining the idea that theories describe a unique underlying ontology. In this paper, we develop a new perspective on scientific realism that responds to…

History and Philosophy of Physics · Physics 2025-12-22 Richard Dawid , Guilherme Franzmann

This paper is a review of our recent work on three notorious problems of non-relativistic quantum mechanics: realist interpretation, quantum theory of classical properties and the problem of quantum measurement. A considerable progress has…

Quantum Physics · Physics 2013-03-01 Petr Hajicek

It is argued that a realistic interpretation of quantum mechanics is possible and useful. Current interpretations, from Copenhagen to many worlds are critically revisited. The difficulties for intuitive models of quantum physics are pointed…

Quantum Physics · Physics 2017-01-11 Emilio Santos

Several new physics experiments in 1998 were performed and analyzed to show the subtlety of quantum theory, including the "wave-particle duality" and the non-separability of two-particle entangled state. Here it is shown that the…

Quantum Physics · Physics 2007-05-23 Guang-jiong Ni

Scientific realism is the philosophical stance that science tracks truth, in particular in its depiction of the world's ontology. Ontologically, this involves a commitment to the existence of entities posited by our best scientific…

History and Philosophy of Physics · Physics 2025-07-30 Raoni Arroyo , Jonas R. Becker Arenhart

I investigate some properties of proposed definitions for subsystem/mixed state complexity and uncomplexity. A very strong dependence arises on the density matrix's degeneracy which gives a large separation in the scaling of maximum…

Quantum Physics · Physics 2019-01-02 Henry Stoltenberg

Some skeptical arguments on the physical reality of quantum states are given. First, I argue that the algebraic formalism of quantum field theory in curved spacetime (algebraic QFTCS, AQFTCS) leads to such a skepticism. Of course we have…

Quantum Physics · Physics 2026-04-15 Hideyasu Yamashita

We use a simple example to illustrate why it is not possible to consider that a measurement reveals an underlying objective reality of a property of a quantum system, that continues the same after the measurement is performed. This kind of…

Quantum Physics · Physics 2020-07-06 Pablo L. Saldanha

This work addresses a fundamental problem of controllability of open quantum systems, meaning the ability to steer arbitrary initial system density matrix into any final density matrix. We show that under certain general conditions open…

Quantum Physics · Physics 2012-10-09 Alexander Pechen

Protective measurement, which was proposed as a method of observing the wavefunction of a single system, is extended to the observation of the density matrix of a single system. d'Espagnat's definition of `proper mixture' is shown to be…

Quantum Physics · Physics 2007-05-23 Y. Aharonov , J. Anandan