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Related papers: Time in Quantum Mechanics

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In this article we study the nature of time in Mechanics. The fundamental principle, according to which a mechanical system evolves governed by a second order differential equation, implies the existence of an absolute time-duration in the…

Mathematical Physics · Physics 2018-09-21 J. Muñoz-Díaz , R. J. Alonso-Blanco

Although the Hamiltonian in quantum physics has to be a linear operator, it is possible to make quantum systems behave as if their Hamiltonians contained antilinear (i.e., semilinear or conjugate-linear) terms. For any given quantum system,…

Mathematical Physics · Physics 2013-01-03 Michael Eisele

We define a quantum-mechanical time operator that is selfadjoint and compatible with the energy operator having a spectrum bounded from below. On their common domain, the operators of time and energy satisfy the expected canonical…

Quantum Physics · Physics 2009-11-10 J. M. Isidro

As time is not an observable, we use Fisher information (FI) to address the problem of time. We show that the Hamiltonian constraint operator cannot be used to analyze any quantum process for quantum geometries that are associated with…

General Relativity and Quantum Cosmology · Physics 2022-09-27 Salman Sajad Wani , James Q. Quach , Mir Faizal

Quantum timeless approaches solve the problem of time by recovering the usual unitary evolution of quantum theory relative to a clock in a stationary quantum Universe. For some Hamiltonians of the Universe, such as those including an…

Quantum Physics · Physics 2026-04-14 Simone Rijavec

We examine the longstanding problem of introducing a time observable in Quantum Mechanics; using the formalism of positive-operator-valued measures we show how to define such an observable in a natural way and we discuss some consequences.

Quantum Physics · Physics 2009-10-30 Riccardo Giannitrapani

The standard formulation of quantum theory assumes a predefined notion of time. This is a major obstacle in the search for a quantum theory of gravity, where the causal structure of space-time is expected to be dynamical and fundamentally…

Quantum Physics · Physics 2016-07-29 Ognyan Oreshkov , Nicolas J. Cerf

When compared to quantum mechanics, classical mechanics is often depicted in a specific metaphysical flavour: spatio-temporal realism or a Newtonian "background" is presented as an intrinsic fundamental classical presumption. However, the…

General Physics · Physics 2025-05-30 C. Baumgarten

We give a review of concepts related to connection of classical and quantum theories, from the phase space perspective. Quantum theory is described by non-commutative operators of coordinates and momenta, results in values having a certain…

Quantum Physics · Physics 2025-09-04 Miloš D. Davidović , Ljubica D. Davidović , Milena D. Davidović

Several novel approaches have been proposed to resolve the problem of time by relating it to change. We argue using quantum information theory that the Hamiltonian constraint in quantum gravity cannot probe change, so it cannot be used to…

General Relativity and Quantum Cosmology · Physics 2022-02-07 Salman Sajad Wani , James Q. Quach , Mir Faizal , Sebastian Bahamonde , Behnam Pourhassan

It is brought forward that viable theories of the physical world that have no variable at all that can play the role of time, do not exist; some notion of time is one of the very first ingredients a candidate theory should possess. Almost…

Quantum Physics · Physics 2018-04-05 Gerard t Hooft

Time in quantum mechanics is peculiar: it is an observable that cannot be associated to an Hermitian operator. As a consequence it is impossible to explain dynamics in an isolated system without invoking an external classical clock, a fact…

Quantum Physics · Physics 2022-01-25 Tommaso Favalli , Augusto Smerzi

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

We study the problem of computing the probability for the time-of-arrival of a quantum particle at a given spatial position. We consider a solution to this problem based on the spectral decomposition of the particle's (Heisenberg) state…

Quantum Physics · Physics 2009-10-30 Norbert Grot , Carlo Rovelli , Ranjeet S. Tate

A new interpretation of quantum mechanics, similar to the Copenhagen interpretation, is developed from time-symmetry arguments and commonly held principles concerning time and causality. These principles, which are grounded in ideas outside…

Quantum Physics · Physics 2007-05-23 William R. Wharton

In the early 2000s, the study of time operators advanced as one of the methods to understand the problem of time as mathematical science. However, the starting point for the time operator is to understand time as a problem of observation…

Quantum Physics · Physics 2020-01-10 Tadashi Fujimoto

A geometric construction of the arrival time in conventional quantum mechanics is presented. It is based on a careful mathematical analysis of different quantization procedures for classical observables as functions of positions and…

Quantum Physics · Physics 2023-06-14 Jerzy Kijowski

The time operator canonically conjugated to the Hamiltonian of $N$ interacting particles on the line is constructed using SU(1,1) as a dynamical symmetry. This hidden conformal symmetry enables us to make a group theoretic analysis of the…

Quantum Physics · Physics 2007-05-23 I. Andric , M. Martinis

We present a generic way of thinking about time machines from the view of a far away observer. In this model the universe consists of three (or more) regions: One containing the entrance of the time machine, another the exit and the…

Quantum Physics · Physics 2007-05-23 Frank Antonsen , Karsten Bormann

The question of how long a particle takes to pass through a potential barrier is still a controversial topic in quantum mechanics. Arguably, the main theoretical problem in obtaining estimates for measurable times is the fact that…

Quantum Physics · Physics 2018-09-19 Ricardo Ximenes , Fernando Parisio , Eduardo O. Dias