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The theory of decoherent histories is an attempt to derive classical physics from positing only quantum laws at the fundamental level without notions of a classical apparatus or collapse of the wave-function. Searching for a marked target…

Quantum Physics · Physics 2013-08-08 Wim van Dam , Hieu D. Nguyen

In spite of its popularity, it has not been possible to vindicate the conventional wisdom that classical mechanics is a limiting case of quantum mechanics. The purpose of the present paper is to offer an alternative formulation of classical…

Quantum Physics · Physics 2015-02-16 Partha Ghose

Quantum Theory, similar to Relativity Theory, requires a new concept of space-time, imposed by a universal constant. While velocity of light $c$ not being infinite calls for a redefinition of space-time on large and cosmological scales,…

History and Philosophy of Physics · Physics 2021-04-21 Herbert Capellmann

Active matter denotes a system of particles immersed in an external environment, from which the particles extract energy continuously in order to perform directed motion. Extending the paradigm of active matter to a quantum framework…

A definition is given and the physical meaning of quantum transformations of a non-commutative configuration space (quantum group coactions) is discussed. It is shown that non-commutative coordinates which are transformed by quantum groups…

High Energy Physics - Theory · Physics 2008-02-03 Andrei Demichev

Why is it that a ticking clock typically becomes less accurate when subject to outside noise but rarely the reverse? Here, we formalize this phenomenon by introducing process causal asymmetry - a fundamental difference in the amount of past…

Quantum Physics · Physics 2023-09-26 Spiros Kechrimparis , Mile Gu , Hyukjoon Kwon

The theory of quantum states over time provides an approach to the dynamics of quantum information which is in direct analogy with spacetime and its relation to classical dynamics. In this work, we further such an analogy by formulating a…

Quantum Physics · Physics 2023-11-02 James Fullwood

Here we prove that the classical (respectively, quantum) system, consisting of a particle moving in a static electromagnetic field, is canonically (respectively, unitarily) equivalent to a harmonic oscillator perturbed by a spatially…

Quantum Physics · Physics 2023-06-27 Henryk Gzyl

Discussions of quantum mechanics often loosely claim that time evolution logically must be unitary, in order for the probabilistic interpretation of the amplitudes of the state vector to make sense at all times. We discuss from first…

Quantum Physics · Physics 2025-02-25 Edward Parker

We investigate a linear operator associated with a functional equation that arises from studying some class of invariant measures under multidimensional transformations. By examining its iterates, we derive an explicit solution formula for…

Functional Analysis · Mathematics 2026-03-09 Oleksandr V. Maslyuchenko , Janusz Morawiec , Thomas Zürcher

In classical mechanics, an action is defined only modulo additive terms which do not modify the equations of motion; in certain cases, these terms are topological quantities. We construct an infinite sequence of higher order topological…

High Energy Physics - Theory · Physics 2008-11-26 Roman V. Buniy , Thomas W. Kephart

The operational formulations of quantum theory are drastically time oriented. However, to the best of our knowledge, microscopic physics is time-symmetric. We address this tension by showing that the asymmetry of the operational…

Quantum Physics · Physics 2021-08-11 Andrea Di Biagio , Pietro Donà , Carlo Rovelli

The theory of $q$-analogs frequently occurs in a number of areas, including the fractals and dynamical systems. The $q$-derivatives and $q$-integrals play a prominent role in the study of $q$-deformed quantum mechanical simple harmonic…

Complex Variables · Mathematics 2017-08-29 S. Kanas , S. Altinkaya , S. Yalcin

After two decades of research on indefinite causality, a philosophical lesson emerges: the tension between operational quantum theory and dynamical spacetime physics is unbridgeable if one believes both types of theories to be fundamental.…

Quantum Physics · Physics 2025-12-30 Alexei Grinbaum

We define the pull-back operator, associated to a meromorphic transform, on several types of currents. We also give a simple proof to a version of a classical theorem on the extension of currents.

Complex Variables · Mathematics 2007-05-23 Tien-Cuong Dinh , Nessim Sibony

Non-commutativity is ubiquitous in mathematical modeling of reality and in many cases same algebraic structures are implemented in different situations. Here we consider the canonical commutation relation of quantum theory and discuss a…

Quantum Physics · Physics 2010-12-30 Pawel Blasiak

The basic ingredients of the `consistent histories' approach to a generalized quantum theory are `histories'and decoherence functionals. The main aim of this program is to find and to study the behaviour of consistent sets associated with a…

General Relativity and Quantum Cosmology · Physics 2009-10-28 S. Schreckenberg

A translation operator is introduced to describe the quantum dynamics of a position-dependent mass particle in a null or constant potential. From this operator, we obtain a generalized form of the momentum operator as well as a unique…

Quantum Physics · Physics 2015-05-30 R. N. Costa Filho , M. P. Almeida , G. A. Farias , J. S. Andrade

It has long been known that there exists a coordinate transformation which exactly maps the quantum free particle to the quantum harmonic oscillator. Here we extend this result by reformulating it as a unitary operation followed by a time…

Quantum Physics · Physics 2022-11-23 Gerard McCaul , Denys I. Bondar

The unitary operator which transforms a harmonic oscillator system of time-dependent frequency into that of a simple harmonic oscillator of different time-scale is found, with and without an inverse-square potential. It is shown that for…

Quantum Physics · Physics 2009-11-06 Dae-Yup Song