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Related papers: Self-adjointness in Quantum Mechanics: a pedagogic…

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Standard quantum mechanics predicts the non-conservation of state norms and probability when the fundamental requirement of the Hermiticity of the Hamiltonian is relaxed. Biorthogonal quantum mechanics, or the more general metric formalism,…

Quantum Physics · Physics 2025-07-18 Mario Gonzalez , Karin Sim , R. Chitra

Recently a study of the first superposed mechanical quantum object ("machine") visible to the naked eye was published. However, as we show, it turns out that if the object would actually be observed, i.e. would interact with an optical…

General Physics · Physics 2015-04-01 Johan Hansson

Quantum correlations in composite and separable quantum systems are characterized by non-vanishing quantum discord. We demonstrate the necessary and sufficient conditions for existence of hermitian witness operators for quantum discord,…

Quantum Physics · Physics 2013-01-01 S. Adhikari , A. S. Majumdar , I. Chakraborty

Formalizations of quantum information theory in category theory and type theory, for the design of verifiable quantum programming languages, need to express its two fundamental characteristics: (1) parameterized linearity and (2) metricity.…

Quantum Physics · Physics 2026-04-07 Hisham Sati , Urs Schreiber

In quantum theory, real degrees of freedom are usually described by operators which are self-adjoint. There are, however, exceptions to the rule. This is because, in infinite dimensional Hilbert spaces, an operator is not necessarily…

High Energy Physics - Theory · Physics 2009-10-31 A. Kempf

We have previously presented a version of the Weak Equivalence Principle for a quantum particle as an exact analog of the classical case, based on the Heisenberg picture analysis of free particle motion. Here, we take that to a full…

General Relativity and Quantum Cosmology · Physics 2025-06-17 Otto C. W. Kong

A non-associative algebra of observables cannot be represented as operators on a Hilbert space, but it may appear in certain physical situations. This article employs algebraic methods in order to derive uncertainty relations and…

High Energy Physics - Theory · Physics 2015-03-31 Martin Bojowald , Suddhasattwa Brahma , Umut Buyukcam , Thomas Strobl

Observables are believed that they must be Hermitian in quantum theory. Based on the obviously physical fact that only eigenstates of observable and its corresponding probabilities, i.e., spectrum distribution of observable are actually…

Quantum Physics · Physics 2017-01-06 Meng-Jun Hu , Xiao-Min Hu , Yong-Sheng Zhang

It is well known that nonrelativistic quantum mechanics presents a clear asymmetry between space and time. Much of this asymmetry is attributed to the lack of Lorentz invariance of the theory. Nonetheless, a recent work [Phys. Rev. A…

Quantum Physics · Physics 2017-12-12 Ricardo Ximenes , Eduardo O. Dias

In "Self-adjoint Operators as Functions I: Lattices, Galois Connections, and the Spectral Order" [arXiv:1208.4724], it was shown that self-adjoint operators affiliated with a von Neumann algebra N can equivalently be described as certain…

Mathematical Physics · Physics 2013-12-06 Andreas Doering , Barry Dewitt

A scheme for constructing quantum mechanics is given that does not have Hilbert space and linear operators as its basic elements. Instead, a version of algebraic approach is considered. Elements of a noncommutative algebra (observables) and…

Quantum Physics · Physics 2015-05-13 D. A. Slavnov

In the many worlds community seems to exist a belief that the physics of a quantum theory is completely defined by it's Hamilton operator given in an abstract Hilbert space, especially that the position basis may be derived from it as…

Quantum Physics · Physics 2009-05-07 Ilja Schmelzer

Deformation quantization and geometric quantization on K\"ahler manifolds give the mathematical description of the algebra of quantum observables and the Hilbert spaces respectively, where the later forms a representation of quantum…

Differential Geometry · Mathematics 2020-10-28 Naichung Conan Leung , Qin Li , Ziming Nikolas Ma

The mathematical formulation of Quantum Mechanics in terms of complex Hilbert space is derived for finite dimensions, starting from a general definition of "physical experiment" and from five simple Postulates concerning "experimental…

Quantum Physics · Physics 2007-05-23 Giacomo Mauro D'Ariano

A source of much difficulty and confusion in the interpretation of quantum mechanics is a ``naive realism about operators.'' By this we refer to various ways of taking too seriously the notion of operator-as-observable, and in particular to…

Quantum Physics · Physics 2007-05-23 Martin Daumer , Detlef Dürr , Sheldon Goldstein , Nino Zangh\`ı

The necessity of complex numbers in quantum mechanics has long been debated. This paper develops a real Kahler space formulation of quantum mechanics [19], asserting equivalence to the standard complex Hilbert space framework. By mapping…

Quantum Physics · Physics 2025-06-10 Irina Aref'eva , Igor Volovich

Any two infinite-dimensional (separable) Hilbert spaces are unitarily isomorphic. The sets of all their self-adjoint operators are also therefore unitarily equivalent. Thus if all self-adjoint operators can be observed, and if there is no…

Quantum Physics · Physics 2009-11-06 A. P. Balachandran

We construct the algebra of operators acting on the Hilbert spaces of Quantum Mechanics for systems of $N$ identical particles from the field operators acting in the Fock space of Quantum Field Theory by providing the explicit relation…

Quantum Physics · Physics 2021-11-10 Nuno Barros e Sá , Cláudio Gomes

We constructed a Hilbert space representation of a contextual Kolmogorov model. This representation is based on two fundamental observables -- in the standard quantum model these are position and momentum observables. This representation…

Quantum Physics · Physics 2015-06-26 Andrei Khrennikov

The Hermiticity axiom of quantum mechanics guarantees that the energy spectrum is real and the time evolution is unitary (probability-preserving). Nevertheless, non-Hermitian but $\mathcal{PT}$-symmetric Hamiltonians may also have real…

Quantum Physics · Physics 2018-06-06 Fernando Quijandría , Uta Naether , Sahin K. Özdemir , Franco Nori , David Zueco