Work

Finite-size clocks in quantum field theory and the twin paradox

Year: 2026

Type: article

Abstract: Vacuum fluctuations in quantum field theory impose fundamental limitations on our ability to measure time at arbitrarily short scales. To investigate the impact of universal quantum field theory effects on observer-dependent time measurements, we introduce a clock model based on the vacuum decay probability of a finite-sized quantum system. This model defines an effective notion of proper time that depends on the microscopic properties of the clock and on how it samples vacuum fluctuations along its trajectory. We show that, in the long-time regime, this notion of time reduces to the usual proper time of special relativity. However, by studying a microscopic twin-paradox scenario, we find that, in general, time is not determined solely by the trajectory connecting two events, but also by how vacuum fluctuations interact with the internal structure of the clocks.

Source: Physical Review Research

DOI: 10.1103/5yl5-4kdk

Authors: Matheus H. Zambianco, T. Rick Perche

Institutions: University of Waterloo, Perimeter Institute, Nordic Institute for Theoretical Physics, Stockholm University, KTH Royal Institute of Technology

Language: English

Topic: Noncommutative and Quantum Gravity Theories

Subfield: Statistical and Nonlinear Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625