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Related papers: Quantum measurements of time

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In quantum mechanics, time is introduced as a non-measurable quantity, as there is no possibility to build a hermitian operator canonically conjugated to the Hamiltonian. We cannot have, therefore, the time operator, which means that the…

Quantum Physics · Physics 2020-03-27 Andrzej Góźdź , Marek Góźdź

The problem of time in the quantization of gravity arises from the fact that time in Schroedinger's equation is a parameter. This sets time apart from the spatial coordinates, represented by operators in quantum mechanics (QM). Thus "time"…

General Relativity and Quantum Cosmology · Physics 2016-05-06 M. Bauer

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

We provide a decision-theoretic framework for dealing with uncertainty in quantum mechanics. This uncertainty is two-fold: on the one hand there may be uncertainty about the state the quantum system is in, and on the other hand, as is…

Quantum Physics · Physics 2026-05-01 Keano De Vos , Gert de Cooman , Alexander Erreygers , Jasper De Bock

It is shown that in presence of certain external fields a well defined self-adjoint time operator exists, satisfying the standard canonical commutation relations with the Hamiltonian. Examples include uniform electric and gravitational…

Quantum Physics · Physics 2023-12-15 A. M. Schlichtinger , A. Jadczyk

While the microscopic laws of physics are often symmetric under time reversal, most natural processes that we observe are not. The emergent asymmetry between typical and time-reversed processes is referred to as the arrow of time. In…

Quantum Physics · Physics 2025-12-23 Luis Pedro García-Pintos , Yi-Kai Liu , Alexey V. Gorshkov

A natural approach to measure the time of arrival of an atom at a spatial region is to illuminate this region with a laser and detect the first fluorescence photons produced by the excitation of the atom and subsequent decay. We investigate…

Quantum Physics · Physics 2009-11-10 J. A. Damborenea , I. L. Egusquiza , G. C. Hegerfeldt , J. G. Muga

The histories-based framework of Quantum Measure Theory assigns a generalized probability or measure $\mu(E)$ to every (suitably regular) set $E$ of histories. Even though $\mu(E)$ cannot in general be interpreted as the expectation value…

Quantum Physics · Physics 2017-01-27 Álvaro Mozota Frauca , Rafael Dolnick Sorkin

Time plays a crucial role in the intuitive understanding of the world around us. Within quantum mechanics, however, time is not usually treated as an observable quantity; it enters merely as a parameter in the laws of motion of physical…

Quantum Physics · Physics 2015-06-05 Sandra Ranković , Yeong-Cherng Liang , Renato Renner

Quantum mechanics and general relativity have been each successfully tested in numerous experiments. However, the regime where both theories are jointly required to explain physical phenomena remains untested by laboratory experiments, and…

Quantum Physics · Physics 2016-07-15 Magdalena Zych , Igor Pikovski , Fabio Costa , Časlav Brukner

Quantum measurements can be described by operators that assign conditional probabilities to different outcomes while also describing unavoidable physical changes to the system. Here, we point out that operators describing information gain…

Quantum Physics · Physics 2026-05-18 Hollis Williams , Holger F. Hofmann

The standard formulation of quantum theory relies on a fixed space-time metric determining the localisation and causal order of events. In general relativity, the metric is influenced by matter, and is expected to become indefinite when…

Quantum Physics · Physics 2020-06-08 Esteban Castro-Ruiz , Flaminia Giacomini , Alessio Belenchia , Časlav Brukner

We review recent progress in understanding the arrival time problem in quantum mechanics, from the point of view of the decoherent histories approach to quantum theory. We begin by discussing the arrival time problem, focussing in…

Quantum Physics · Physics 2015-05-20 James M Yearsley

Quantum measurement and quantum operation theory is developed here by taking the relational properties among quantum systems, instead of the independent properties of a quantum system, as the most fundamental elements. By studying how the…

Quantum Physics · Physics 2021-04-20 Jianhao M. Yang

In these notes, based on lectures given as part of the Les Houches summer school on Quantum Optics and Nanophotonics in August, 2013, I have tried to give a brief survey of some important approaches and modern tendencies in quantum…

Quantum Physics · Physics 2014-06-24 Aephraim M. Steinberg

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

We further develop the general theory of quantum time distributions introduced in arXiv:2010.07575 and apply it to find the distribution of arrival times at the detector. Even though the Hamiltonian in the absence of detector is hermitian,…

Quantum Physics · Physics 2022-06-01 Tajron Jurić , Hrvoje Nikolić

Probabilities in quantum theory are traditionally given by Born's rule as the expectation values of projection operators. Here it is shown that Born's rule is insufficient in universes so large that they contain identical multiple copies of…

High Energy Physics - Theory · Physics 2010-03-15 Don N. Page

We propose a covariant algorithm for relativistic ideal measurements and for relativistic continuous measurements, its non-relativistic limit results the algorithm of the Event-Enhanced Quantum Theory. Therefore an additional intrinsic…

Quantum Physics · Physics 2007-05-23 Andreas Ruschhaupt

The notion of probability plays a crucial role in quantum mechanics. It appears in quantum mechanics as the Born rule. In modern mathematics which describes quantum mechanics, however, probability theory means nothing other than measure…

Quantum Physics · Physics 2025-12-04 Kohtaro Tadaki