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Related papers: "Time operator": the challenge persists

200 papers

Motivated by the parametrization invariance of cosmological Lagrangians and their equivalence to systems describing the motion of particles in curved backgrounds, we identify the phase space analogue of the notion of proper time. We define…

General Relativity and Quantum Cosmology · Physics 2025-04-15 N. Dimakis

The notions of time in the theories of Newton and Einstein are reviewed so that certain of their assumptions are clarified. These assumptions will be seen as the causes of the incompatibility between the two different ways of understanding…

General Relativity and Quantum Cosmology · Physics 2008-02-03 Hitoshi Kitada , Lancelot R. Fletcher

Within the framework of self-adjoint operator of time in non-relativistic quantum mechanics the equation describing change of the state of quantum system with respect to energy is introduced. The operator of time appears to be the generator…

Quantum Physics · Physics 2017-01-20 Slobodan Prvanovic

This paper gives a representation of the most general positive operator valued measure in Minkowski space-time, covariant with respect to the Poincare' group. It provides the correct mathematical description of the space-time coordinates of…

Quantum Physics · Physics 2008-02-03 M. Toller

In this work we discuss the notion of observable - both quantum and classical - from a new point of view. In classical mechanics, an observable is represented as a function (measurable, continuous or smooth), whereas in (von Neumann's…

Mathematical Physics · Physics 2007-05-23 Hans F. de Groote

Time in relativity theory has a status different from that adopted by standard quantum mechanics, where time is considered as a parameter measured with reference to an external absolute Newtonian frame. This status strongly restricts its…

Quantum Physics · Physics 2023-10-26 M. Basil Altaie

The classical Hilbert space formulation of the axioms of Quantum Mechanics appears to leave open the question whether the Hermitian operators which are associated with the observables of a finite non-relativistic quantum system are uniquely…

Quantum Physics · Physics 2007-05-23 E. E. Rosinger

Although the quantization of relativistic systems in a proper-time framework gives new insights concerning the understanding of the so-called localization problem, classical observers cannot be treated as quantum comoving frames and real…

Quantum Physics · Physics 2021-07-27 E. R. F. Taillebois , A. T. Avelar

An operational time of arrival is introduced using a realistic position and momentum measurement scheme. The phase space measurement involves the dynamics of a quantum particle probed by a measuring device. For such a measurement an…

Quantum Physics · Physics 2009-10-31 Piotr Kochanski , Krzysztof Wodkiewicz

The relation between quantum measurement and thermodynamically irreversible processes is investigated. The reduction of the state vector is fundamentally asymmetric in time and shows an observer-relatedness which may explain the double…

Quantum Physics · Physics 2015-06-26 H. D. Zeh

We propose a time-of-arrival operator in quantum mechanics by conditioning on a quantum clock. This allows us to bypass some of the problems of previous proposals, and to obtain a Hermitian time of arrival operator whose probability…

Quantum Physics · Physics 2020-03-19 Lorenzo Maccone , Krzysztof Sacha

The question of how to interpret and compute arrival-time distributions in quantum mechanics remains unsettled, reflecting the longstanding tension between treating time as a quantum observable or as a classical parameter. Most previous…

It is unclear whether an observable notion of time exists in quantum gravity even in principle because spacetime itself fluctuates. We propose a form of observable time in perturbative quantum gravity. First, we define an elapsed proper…

High Energy Physics - Theory · Physics 2025-06-23 Allic Sivaramakrishnan

The recursion operators and symmetries of non-autonomous, (1+1)-dimensional integrable evolution equations are considered. It has been previously observed that the symmetries of the integrable evolution equations obtained through their…

Exactly Solvable and Integrable Systems · Physics 2015-06-26 Metin Gurses , Atalay Karasu , Refik Turhan

In general relativity, cosmology and quantum field theory, spacetime is assumed to be an orientable manifold endowed with a Lorentz metric that makes it spatially and temporally orientable. The question as to whether the laws of physics…

General Relativity and Quantum Cosmology · Physics 2023-06-08 N. A. Lemos , D. Müller , M. J. Reboucas

We provide the most general forms of covariant and normalized time operators and their probability densities, with applications to quantum clocks, the time of arrival, and Lyapunov quantum operators. Examples are discussed of the profusion…

Quantum Physics · Physics 2015-05-19 G. C. Hegerfeldt , J. G. Muga , J. Muñoz

Local operators are the basic observables in quantum field theory which encode the physics observed by a local experimentalist. However, when gravity is dynamical, diffeomorphism symmetries are gauged which apparently obstructs a sensible…

High Energy Physics - Theory · Physics 2025-04-11 Hao Geng

We provide a brief discussion regarding relativistic limits on the discretization and temporal resolution of time values in a quantum clock. Our clock is characterized by a time observable chosen to be the complement of a bounded and…

Quantum Physics · Physics 2025-10-16 Tommaso Favalli

A suitable operator for the time-of-arrival at a detector is defined for the free relativistic particle in 3+1 dimensions. For each detector position, there exists a subspace of detected states in the Hilbert space of solutions to the Klein…

Quantum Physics · Physics 2008-11-26 J. Leon

The problem of defining time (or phase) operator for three-dimensional harmonic oscillator has been analyzed. A new formula for this operator has been derived. The results have been used to demonstrate a possibility of representing…

Quantum Physics · Physics 2009-11-07 Pavel Kundrat , Milos V. Lokajicek