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Related papers: Discrete Quantum Mechanics I: Quantum Covariance

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We consider symmetry as a foundational concept in quantum mechanics and rewrite quantum mechanics and measurement axioms in this description. We argue that issues related to measurements and physical reality of states can be better…

Quantum Physics · Physics 2018-04-11 Houri Ziaeepour

It is shown explicitly that in the framework of Bohmian quantum gravity, the equations of motion of the space-time metric are Einstein's equations plus some quantum corrections. It is observed that these corrections are not covariant. So…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Fatimah Shojai , Mehdi Golshani

We present a formulation of the generalised uncertainty principle based on commutator $\left[ {\hat x}^i, {\hat p}_j \right]$ between position and momentum operators defined in a covariant manner using normal coordinates. We show how any…

General Relativity and Quantum Cosmology · Physics 2022-05-19 Raghvendra Singh , Dawood Kothawala

This paper considers a generalization of the notion of quantum observables in ontological models of quantum mechanics. Within this framework it is possible to construct physical models where quantum noncommutativity can arise dynamically.…

Quantum Physics · Physics 2007-12-12 Tung Ten Yong

Any metric theory of gravity whose interaction with quantum particles is described by a covariant wave equation is equivalent to a vector theory that satisfies Maxwell-type equations identically. This result does not depend on any…

General Relativity and Quantum Cosmology · Physics 2014-04-30 Giorgio Papini

Spacetime must be foliable by spacelike surfaces for the quantum mechanics of matter fields to be formulated in terms of a unitarily evolving state vector defined on spacelike surfaces. When a spacetime cannot be foliated by spacelike…

General Relativity and Quantum Cosmology · Physics 2009-10-22 James B. Hartle

Quantum mechanics is 'emergent' if a statistical treatment of large scale phenomena in a locally deterministic theory requires the use of quantum operators. These quantum operators may allow for symmetry transformations that are not present…

High Energy Physics - Theory · Physics 2008-11-26 Gerard 't Hooft

We study the variances of the coordinates of an event considered as quantum observables in a Poincare' covariant theory. The starting point is their description in terms of a covariant positive-operator-valued measure on the Minkowski…

Quantum Physics · Physics 2016-09-08 M. Toller

Dirac talked about q-numbers versus c-numbers. Quantum observables are q-number variables that generally do not commute among themselves. He was proposing to have a generalized form of numbers as elements of a noncommutative algebra. That…

General Physics · Physics 2024-05-20 Otto C. W. Kong

A set of diverse but mutually consistent results obtained in different settings has spawned a new view of loop quantum gravity and its physical implications, based on the interplay of operator calculations and effective theory: Quantum…

General Relativity and Quantum Cosmology · Physics 2012-12-27 Martin Bojowald

It is shown that quantum mechanics is noncontextual if quantum properties are represented by subspaces of the quantum Hilbert space (as proposed by von Neumann) rather than by hidden variables. In particular, a measurement using an…

Quantum Physics · Physics 2013-02-21 Robert B. Griffiths

We propose a system of equations to describe the interaction of a quasiclassical variable $X$ with a set of quantum variables $x$ that goes beyond the usual mean field approximation. The idea is to regard the quantum system as continuously…

Quantum Physics · Physics 2009-10-30 L. Diosi , J. J. Halliwell

Measurement is a fundamental notion in the usual approximate quantum mechanics of measured subsystems. Probabilities are predicted for the outcomes of measurements. State vectors evolve unitarily in between measurements and by reduction of…

General Relativity and Quantum Cosmology · Physics 2014-01-14 James B. Hartle

We study a tentative generally covariant quantum field theory, denoted the T-Theory, as a tool to investigate the consistency of quantum general relativity. The theory describes the gravitational field and a minimally coupled scalar field;…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Carlo Rovelli

A suitable unified statistical formulation of quantum and classical mechanics in a *-algebraic setting leads us to conclude that information itself is noncommutative in quantum mechanics. Specifically we refer here to an observer's…

Quantum Physics · Physics 2018-07-02 Rocco Duvenhage

Quantum gravity (or quantum spacetime) is to unify general relativity and quantum mechanics into a single theoretical framework and presented as the most important open puzzle in fundamental physics. The development of a microscopic theory…

General Physics · Physics 2025-10-24 Su-Peng Kou

The equivalence postulate approach to quantum mechanics aims to formulate quantum mechanics from a fundamental geometrical principle. Underlying the formulation there exists a basic cocycle condition which is invariant under…

High Energy Physics - Theory · Physics 2018-06-20 Alon E. Faraggi , Marco Matone

The concept of a particle is ambiguous in quantum field theory. It is generally agreed that particles depend not only on spacetime, but also on coordinates used to parametrise spacetime points. One of us has in contrast proposed a…

General Relativity and Quantum Cosmology · Physics 2026-04-07 V. A. Emelyanov , D. Robertz

The generalized uncertainty principle has been described as a general consequence of incorporating a minimal length from a theory of quantum gravity. We consider a simple quantum mechanical model where the operator corresponding to position…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jang Young Bang , Micheal S. Berger

Standard quantum mechanics undeniably violates the notion of separability that classical physics accustomed us to consider as valid. By relating the phenomenon of quantum nonseparability to the all-important concept of potentiality, we…

Quantum Physics · Physics 2008-11-25 Vassilios Karakostas