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Time continues to be an intriguing physical property in the modern era. On the one hand, we have the Classical and Relativistic notion of time, where space and time have the same hierarchy, which is essential in describing events in…

Quantum Physics · Physics 2022-12-29 Arlans JS de Lara , Marcus W Beims

An extension of standard quantum mechanics is proposed in which the Newtonian time appearing as a parameter in the unitary evolution operator is replaced with the time shown by a `quantum clock'. Such a clock is defined by the following…

Quantum Physics · Physics 2026-03-17 Dorje C. Brody , Lane P. Hughston

In order to study the "problem of time", Rovelli proposed a model of a two harmonic oscillator system where one of the oscillators can be thought of as a 'clock' for the other oscillator. In this paper we examine a model where the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Yoshiaki Ohkuwa

The Wigner time delay, defined by the energy derivative of the total scattering phase shift, is an important spectral measure of an open quantum system characterising the duration of the scattering event. It is related to the trace of the…

Chaotic Dynamics · Physics 2014-12-12 Jack Kuipers , Dmitry V. Savin , Martin Sieber

The construction of a class of unitary operators generating linear superpositions of generalized coherent states from the ground state of a quantum harmonic oscillator is reported. Such a construction, based on the properties of a new ad…

Quantum Physics · Physics 2013-06-13 Antonino Messina , Gheorghe Draganescu

We review the spectral analysis and the time-dependent approach of scattering theory for manifolds with asymptotically cylindrical ends. For the spectral analysis, higher order resolvent estimates are obtained via Mourre theory for both…

Mathematical Physics · Physics 2011-08-26 S. Richard , R. Tiedra de Aldecoa

We study the limitations for defining spatial and temporal intervals when the only available reference frame is a single composite quantum system, whose internal degrees of freedom serve as a temporal reference, a clock, and whose center of…

Quantum Physics · Physics 2026-01-27 Davide Mattei , Esteban Castro-Ruiz

We argue that (1) our perception of time through change and (2) the gap between reality and our observation of it are at the heart of both quantum mechanics and the dynamical mechanism of physical systems. We suggest that the origin of…

General Physics · Physics 2014-07-15 Michael York

The self adjoint operator of time in non-relativistic quantum mechanics is found within the approach where the ordinary Hamiltonian is not taken to be conjugate to time. The operator version of the reexpressed Liouville equation with the…

Quantum Physics · Physics 2011-11-03 Slobodan Prvanovic

The problem of time is one of the most relevant open issues in canonical quantum gravity. Although there is a huge literature about this topic, a commonly accepted solution has not been found yet. Here, we focus on the semiclassical…

General Relativity and Quantum Cosmology · Physics 2021-05-18 Federico Di Gioia , Giulia Maniccia , Giovanni Montani , Jacopo Niedda

Previously we presented general formulation of hidden time concept as a basis for building a dynamical picture underlying quantum mechanics. Here, we present detailed explanation of how hidden time works for basic quantum optical…

General Physics · Physics 2007-05-23 Pavel V. Kurakin

The main motivation of this article is to derive sufficient conditions for dynamical stability of periodically driven quantum systems described by a Hamiltonian H(t), i.e., conditions under which it holds sup_{t in R} | (psi(t),H(t) psi(t))…

Mathematical Physics · Physics 2009-11-13 Pierre Duclos , Eric Soccorsi , Pavel Stovicek , Michel Vittot

The paper addresses the quantization of minisuperspace cosmological models by studying a possible solution to the problem of time and time asymmetries in quantum cosmology. Since General Relativity does not have a privileged time variable…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mario Castagnino , Gabriel Catren , Rafael Ferraro

We consider a global quantum system (the "Universe") satisfying a double constraint, both on total energy and total momentum. Generalizing the Page and Wootters quantum clock formalism, we provide a model of 3+1 dimensional,…

Quantum Physics · Physics 2022-11-10 Tommaso Favalli , Augusto Smerzi

Given a bipartite quantum system in an energy eigenstate, the dynamical description for one component can be derived via entanglement using the other component as a clock. This is the essence of the Page and Wootters mechanism. Moreover, if…

The expected return time to the original state is a key concept characterizing systems obeying both classical or quantum dynamics. We consider iterated open quantum dynamical systems in finite dimensional Hilbert spaces, a broad class of…

Quantum Physics · Physics 2015-04-16 P. Sinkovicz , Z. Kurucz , T. Kiss , J. K. Asbóth

An extrinsic time is identified in most isotropic and homogeneous cosmological models by matching them with the ideal clock - a parametrized system whose only "degree of freedom" is time -. Once this matching is established, the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 S. C. Beluardi , Rafael Ferraro

The local conservation of a physical quantity whose distribution changes with time is mathematically described by the continuity equation. The corresponding time parameter, however, is defined with respect to an idealized classical clock.…

Chemical Physics · Physics 2018-11-21 Axel Schild

In this work quantum physics in noncommutative spacetime is developed. It is based on the work of Doplicher et al. which allows for time-space noncommutativity. The Moyal plane is treated in detail. In the context of noncommutative quantum…

High Energy Physics - Theory · Physics 2016-09-06 A. P. Balachandran , T. R. Govindarajan , C. Molina , P. Teotonio-Sobrinho

Quantum canonical transformations corresponding to time-dependent diffeomorphisms of the configuration space are studied. A special class of these transformations which correspond to time-dependent dilatations is used to identify a…

Quantum Physics · Physics 2008-11-26 Ali Mostafazadeh