English

Notes on time entanglement and pseudo-entropy

High Energy Physics - Theory 2024-04-29 v3

Abstract

Following arXiv:2210.12963 [hep-th], we investigate aspects of the time evolution operator regarded as a density operator and associated entanglement-like structures in various quantum systems. These involve timelike separations and generically lead to complex-valued entropy, although there are interesting real subfamilies. There are many parallels and close relations with reduced transition matrices and pseudo-entropy, which we discuss and clarify. For instance, a related quantity involves the time evolution operator along with a projection onto some initial state, which amounts to analysing pseudo-entropy for the initial state and its time-evolved final state.

Keywords

Cite

@article{arxiv.2303.01307,
  title  = {Notes on time entanglement and pseudo-entropy},
  author = {K. Narayan and Hitesh K. Saini},
  journal= {arXiv preprint arXiv:2303.01307},
  year   = {2024}
}

Comments

Latex, 32pgs, v2: section on time-dependent potentials added, clarifications added, v3: minor clarifications added, version to be published

R2 v1 2026-06-28T08:57:17.459Z