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  • Open Access

Kappa plane wave modes and continuous squeezing in quantum field theory

Arash Azizi*

  • The Institute for Quantum Science and Engineering, Texas A&M University, College Station, Texas 77843, USA

  • *Contact author: sazizi@tamu.edu
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Phys. Rev. D 112, 025018 – Published 29 July, 2025

DOI: https://doi.org/10.1103/ng6c-yvwm

Abstract

We introduce a new family of field modes in flat spacetime—termed κ-plane wave modes—constructed from κ-dependent linear combinations of Minkowski plane waves. These modes define a one-parameter family of vacua |0κ⟩ that smoothly interpolate between different quantizations, reducing to the Minkowski vacuum in the limit κ→0. We show that |0κ⟩ is uniquely characterized as a continuous-mode squeezed vacuum, with frequency-dependent squeezing parameter r(ν) satisfying tanhr(ν)=e−πν/κ. We also derive two Bogoliubov transformations between κ-plane wave and κ-Rindler operators, which exhibit a universal form and smoothly interpolate between all known mode decompositions, including those of Minkowski, Rindler, and Unruh quantizations as limiting cases.

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Phys. Rev. D 112, 025018– Published 29 July, 2025
  • Received 5 June 2025
  • Accepted 3 July 2025
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