A time operator and the time-of-arrival problem in quantum field theory

• URL: http://arxiv.org/abs/2407.08841v2
• Date: Mon, 30 Jun 2025 18:54:42 GMT
• Title: A time operator and the time-of-arrival problem in quantum field theory
• Authors: Daniele Colosi, Robert Oeckl,
• Abstract summary: We replace the Newton-Wigner states and operator with one-particle states of massive Klein-Gordon theory.<n>We construct one-particle states of massive Klein-Gordon theory that are localized on the hypersurface in the temporal as well as two spatial directions.<n>As in the Newton-Wigner case, localization is not perfect, but apparent superluminal propagation is exponentially suppressed.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The Newton-Wigner states and operator are widely accepted to provide an adequate notion of spatial localization of a particle in quantum field theory on a spacelike hypersurface. Replacing the spacelike with a timelike hypersurface, we construct one-particle states of massive Klein-Gordon theory that are localized on the hypersurface in the temporal as well as two spatial directions. This addresses the longstanding problem of a "time operator" in quantum theory. It is made possible by recent advances in quantization on timelike hypersurfaces and the introduction of evanescent particles. As a first application of time-localized states, we consider the time-of-arrival problem. Our results are in accordance with semiclassical expectations of causal propagation of massless and massive particles. As in the Newton-Wigner case, localization is not perfect, but apparent superluminal propagation is exponentially suppressed.

Related papers

• Temporal Entanglement from Holographic Entanglement Entropy [44.99833362998488]
  We propose a systematic prescription to characterize temporal entanglement in quantum field theory.<n>For holographic quantum field theories, our prescription amounts to an analytic continuation of all co-dimension-two bulk extremal surfaces.<n>We show that it leads to results with self-consistent physical properties of temporal entanglement.
  arXiv  Detail & Related papers  (2025-07-23T18:14:21Z)
• Coordinate- and spacetime-independent quantum physics [0.0]
  The concept of a particle is ambiguous in quantum field theory.<n>One of us has proposed a coordinate-frame-independent model of quantum particles.
  arXiv  Detail & Related papers  (2024-12-05T17:01:32Z)
• Interacting Dirac fields in an expanding universe: dynamical condensates and particle production [41.94295877935867]
  This work focuses on a self-interacting field theory of Dirac fermions in an expanding Friedmann-Robertson-Walker universe.<n>We study how the non-trivialative condensates arise and, more importantly, how their real-time evolution has an impact on particle production.
  arXiv  Detail & Related papers  (2024-08-12T14:21:25Z)
• Area laws from classical entropies [0.0]
  The area law-like scaling of local quantum entropies is the central characteristic of the entanglement inherent in quantum fields, many-body systems, and spacetime. We show that it equally manifests in classical entropies over measurement distributions when vacuum contributions dictated by the uncertainty principle are subtracted.
  arXiv  Detail & Related papers  (2024-04-18T16:52:56Z)
• Looking for Carroll particles in two time spacetime [55.2480439325792]
  Carroll particles with a non-vanishing value of energy are described in the framework of two time physics. We construct the quantum theory of such a particle using an unexpected correspondence between our parametrization and that obtained by Bars for the hydrogen atom in 1999.
  arXiv  Detail & Related papers  (2023-10-29T15:51:41Z)
• Real-time dynamics of false vacuum decay [49.1574468325115]
  We investigate false vacuum decay of a relativistic scalar field in the metastable minimum of an asymmetric double-well potential. We employ the non-perturbative framework of the two-particle irreducible (2PI) quantum effective action at next-to-leading order in a large-N expansion.
  arXiv  Detail & Related papers  (2023-10-06T12:44:48Z)
• Superluminal local operations in quantum field theory: A ping-pong ball test [0.0]
  In quantum field theory, localized operations may lead to non-causal, or superluminal, state changes within their localization region. In classical relativistic field theory, there are localized operations which correspond to instantaneous'' spatial rotations. This article is part of a Special Issue on the 'Physics of Time Travel' in the journal Universe.
  arXiv  Detail & Related papers  (2023-08-31T12:23:10Z)
• Emergent geometric phase in time-dependent noncommutative quantum system [0.0]
  We have given a systematic way to formulate non-relativistic quantum mechanics on 1+1 dimensional NC space-time. Although the effect of noncommutativity of space-time should presumably become significant at a very high energy scale, it is intriguing to speculate that there should be some relics of the effects of quantum space-time even in a low-energy regime.
  arXiv  Detail & Related papers  (2023-06-14T12:29:08Z)
• Quantum dynamics via a hidden Liouville space [0.0]
  We introduce a nonstandard iterative technique where time interval is divided into a large number of discrete subintervals with an ultrashort duration. We choose two-state spin raising and lowering operators for virtual space operators because of their simple algebra. We implement our technique for an example of a charged particle in both harmonic and anharmonic potentials.
  arXiv  Detail & Related papers  (2023-04-18T20:12:06Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)
• Quantum Travel Time and Tunnel Ionization Times of Atoms [0.0]
  We show that the quantum travel time, hypothesized to emerge with the state vector, is a function of the probability density and probability current. We compute it inside and outside a rectangular potential barrier and find physically sensible results. The quantum travel time holds good for stationary systems, and can have applications in numerous tunneling-driven phenomena.
  arXiv  Detail & Related papers  (2020-01-16T21:18:05Z)
• Projection evolution and quantum spacetime [68.8204255655161]
  We discuss the problem of time in quantum mechanics. An idea of construction of a quantum spacetime as a special set of the allowed states is presented. An example of a structureless quantum Minkowski-like spacetime is also considered.
  arXiv  Detail & Related papers  (2019-10-24T14:54:11Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.