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We introduce a geometric formulation of quantum indeterminacy from which the standard uncertainty inequalities emerge as necessary consequences. Our approach is based on convex geometry in phase space and on methods from symplectic…

Quantum Physics · Physics 2026-05-29 Maurice de Gosson

A discussion is given of the quantisation of a physical system with finite degrees of freedom subject to a Hamiltonian constraint by treating time as a constrained classical variable interacting with an unconstrained quantum state. This…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles Wang

The toy model of a particle on a vertical rotating circle in the presence of uniform gravitational/ magnetic fields is explored in detail. After an analysis of the classical mechanics of the problem we then discuss the quantum mechanics…

Quantum Physics · Physics 2009-10-31 Sayan Kar , Avinash Khare

In this paper, we investigate the connection between Classical and Quantum Mechanics by dividing Quantum Theory in two parts: - General Quantum Axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoint…

Quantum Physics · Physics 2009-11-07 H. Bergeron

Canonical coordinates for the Schr\"odinger equation are introduced, making more transparent its Hamiltonian structure. It is shown that the Schr\"odinger equation, considered as a classical field theory, shares with Liouville completely…

High Energy Physics - Theory · Physics 2009-10-30 G. Marmo , G. Vilasi

What is fundamentally quantum? We argue that most of the features, problems, and paradoxes -- such as the measurement problem, the Wigner's friend paradox and its proposed solutions, single particle nonlocality, and no-cloning -- allegedly…

Quantum Physics · Physics 2025-04-09 Flavio Del Santo , Nicolas Gisin

The one particle quantum mechanics is considered in the frame of a N-body classical kinetics in the phase space. Within this framework, the scenario of a subquantum structure for the quantum particle, emerges naturally, providing an…

Quantum Physics · Physics 2009-11-07 G. Kaniadakis

Quantum fields do not satisfy the pointwise energy conditions that are assumed in the original singularity theorems of Penrose and Hawking. Accordingly, semiclassical quantum gravity lies outside their scope. Although a number of…

General Relativity and Quantum Cosmology · Physics 2022-04-13 Christopher J. Fewster , Eleni-Alexandra Kontou

The definitions of classical and quantum singularities in general relativity are reviewed. The occurence of quantum mechanical singularities in certain spherically symmetric and cylindrically symmetric (including infinite line…

General Relativity and Quantum Cosmology · Physics 2007-05-23 D. A. Konkowski , T. M. Helliwell , C. Wieland

Effective classicality of a property of a quantum system can be defined using redundancy of its record in the environment. This allows quantum physics to approximate the situation encountered in the classical world: The information about a…

Quantum Physics · Physics 2007-05-23 W. H. Zurek

Quantum mechanics is one of the basic theories of modern physics. Here, the famous Schr\"odinger equation and the differential operators representing mechanical quantities in quantum mechanics are derived, just based on the principle that…

General Physics · Physics 2021-06-03 Xiao-Bo Yan

The quantum formalism is a ``measurement'' formalism--a phenomenological formalism describing certain macroscopic regularities. We argue that it can be regarded, and best be understood, as arising from Bohmian mechanics, which is what…

Quantum Physics · Physics 2015-06-26 Detlef Dürr , Sheldon Goldstein , Nino Zanghí

We give a short account of the quantisation of the Szekeres spacetime by considering the symmetries of a reduced action principle. This is an alternative approach than the one followed in the literature for the study of inhomogeneities,…

General Relativity and Quantum Cosmology · Physics 2019-12-10 Adamantia Zampeli

There exist dozens of interpretations of quantum theory, but they do not seem to contribute much to understanding the theory. This paper attempts to clarify some issues that are discussed in those interpretations. The main keywords are:…

Quantum Physics · Physics 2020-07-28 Michael Drieschner

Any time-dependent solution of Schr\"{o}dinger equation may be always correlated to a solution of Hamilton equations or to a statistical combination of their solutions; only the set of corresponding solutions is somewhat smaller (due to…

Quantum Physics · Physics 2012-05-31 Milos V. Lokajicek

Within the framework of the individuality interpretation of quantum theory (QT), the basic equations of QT cannot be derived from the basic equations of classical mechanics (CM). The unbridgeable gap between CM and QT is given by the fact…

Quantum Physics · Physics 2025-01-13 Ulf Klein

The usual formulation of quantum theory is rather abstract. In recent work I have shown that we can, nevertheless, obtain quantum theory from five reasonable axioms. Four of these axioms are obviously consistent with both classical…

Quantum Physics · Physics 2007-05-23 Lucien Hardy

Three problems stand in the way of deriving classical theories from quantum mechanics: those of realist interpretation, of classical properties and of quantum measurement. Recently, we have identified some tacit assumptions that lie at the…

Quantum Physics · Physics 2015-06-03 Petr Hajicek

We describe a simple formalism for generating classes of quantum circuits that are classically efficiently simulatable and show that the efficient simulation of Clifford circuits (Gottesman-Knill theorem) and of matchgate circuits…

Quantum Physics · Physics 2008-12-25 Richard Jozsa

Quantum technology is seeing a remarkable explosion in interest due to a wave of successful commercial technology. As a wider array of engineers and scientists are needed, it is time we rethink quantum educational paradigms. Current…

Popular Physics · Physics 2020-03-23 James Daniel Whitfield
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