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On the (Non)Unitarity with respect to the Clock of a Dynamical Local Observer and the Einstein Equivalence Principle — arXiv:2608.16762

Source: arXiv (en)
Original: https://arxiv.org/abs/2608.16762
License (as archived): CC0-1.0
Archived: 2026-10-19T01:05:28.678Z
SHA-256 of the archived text: 1b4a6d60348007e9802abcd170764ed2efa11124986ea6ee6f99a41293314158
Stable URL of this page: https://metraipolis.com/documento/dc_1400a405386f

How to cite

On the (Non)Unitarity with respect to the Clock of a Dynamical Local Observer and the Einstein Equivalence Principle — arXiv:2608.16762 — arXiv (en), https://arxiv.org/abs/2608.16762 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_1400a405386f (Metraipolis archive dc_1400a405386f, sha256 1b4a6d60348007e9802abcd170764ed2efa11124986ea6ee6f99a41293314158)

BibTeX

@misc{dc1400a405386f,
  title = {On the (Non)Unitarity with respect to the Clock of a Dynamical Local Observer and the Einstein Equivalence Principle — arXiv:2608.16762},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2608.16762},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_1400a405386f; sha256 1b4a6d60348007e9802abcd170764ed2efa11124986ea6ee6f99a41293314158},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2608.16762. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

We investigate the unitarity of quantum evolution relative to an internal time defined by a local observer's clock. The observer is modeled as a relativistic particle carrying both a clock and a matter-field detector, analyzed first on a fixed curved background and subsequently within a fully diffeomorphism-invariant theory of dynamical gravity. In the former case, we find that evolution with respect to the internal clock time is generally nonunitary, implying a violation of the Einstein equivalence principle at the quantum level. In contrast, in the latter case, diffeomorphism invariance allows us to adopt observer-centric coordinates without loss of generality. On the resulting partially-reduced phase space, one of the diffeomorphism generators becomes linear in the clock Hamiltonian, generating a relational evolution that is consistent with the remaining diffeomorphism constraints. Assuming that an effective quantum field theory exists to be consistent with the diffeomorphism invariance, these features ensure unitary evolution relative to the internal clock, thereby preserving the equivalence principle even in the quantum regime. Our results highlight the fundamental role of diffeomorphism invariance in shaping relational unitary evolution from the perspective of a local observer.

Tema degli esploratori: fisica e astronomia (retro-catalogo arXiv: annunci del 2026-08-18 in quant-ph).
Categorie arXiv: General Relativity and Quantum Cosmology (gr-qc) ; High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph).
Pagina del lavoro: https://arxiv.org/abs/2608.16762 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-10-19T00:29:15.452Z dalla pagina https://arxiv.org/catchup/quant-ph/2026-08-18?abs=True (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).