Entanglement, Discord, and Residual Coherence in Scalar-Induced Gravitational Waves
Abstract
Scalar-induced gravitational waves (SIGWs) are usually characterized by their power spectrum, although their quadratic scalar source also carries higher-order correlation information. We investigate whether phase-sensitive correlations of a primordial Gaussian scalar state can survive decoherence and be transferred to the induced tensor sector. The scalar state is described in a fixed oscillator basis by the occupation Nkζ and anomalous moment Mkζ, while the transfer is formulated through the unequal-time scalar Wightman function. The late-time tensor moments dk and γk define an effective Gaussian reference state and its discord, whereas the exact SIGW state is generally non-Gaussian and contains an additional connected fourth-order cumulant. We therefore introduce the baseline-subtracted observable Δκcoh=κN[G>coh]−κN[G>ref]. For phase damping with Mkζ∝ e−Dk, the Gaussian-reference contribution conditionally scales as |γk|∝ e−2Dk and κNG∝ e−4Dk. This provides a framework in which the SIGW spectrum fixes the signal band, while higher-order statistics probe residual coherence beyond the power spectrum.
Related
- Correlation Harvesting by Unruh--DeWitt Detectors in a Cylindrical Cavity: Entanglement, Mutual Information, and Quantum Discord
- Newtonian Gravitational Curvature-Induced Entanglement Generation
- Macroscopic quantum coherence and entanglement in mechanical systems
- GR–QM–CCC Interpenetrating Closure: Projection-Compressed Observability, Residual Coherence, and Realization Accessibility
- Dilaton gravity can enhance quantum coherence and reduce entanglement
BibTeX
@misc{ahmed2026entanglement,
title = {{Entanglement, Discord, and Residual Coherence in Scalar-Induced Gravitational Waves}},
author = {Waqas Ahmed},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.21901},
eprint = {2606.21901},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.21901},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Entanglement, Discord, and Residual Coherence in Scalar-Induced Gravitational Waves
AU - Waqas Ahmed
PY - 2026
DA - 2026/09/21
PB - arXiv
DO - 10.48550/arxiv.2606.21901
UR - https://arxiv.org/abs/2606.21901
AB - Scalar-induced gravitational waves (SIGWs) are usually characterized by their power spectrum, although their quadratic scalar source also carries higher-order correlation information. We investigate whether phase-sensitive correlations of a primordial Gaussian scalar state can survive decoherence and be transferred to the induced tensor sector. The scalar state is described in a fixed oscillator basis by the occupation N_k^ζ and anomalous moment M_k^ζ, while the transfer is formulated through the unequal-time scalar Wightman function. The late-time tensor moments d_k and γ_k define an effective Gaussian reference state and its discord, whereas the exact SIGW state is generally non-Gaussian and contains an additional connected fourth-order cumulant. We therefore introduce the baseline-subtracted observable Δκ_coh=κ_N[G^>_coh]−κ_N[G^>_ref]. For phase damping with M_k^ζ∝ e^−D_k, the Gaussian-reference contribution conditionally scales as |γ_k|∝ e^−2D_k and κ_N^G∝ e^−4D_k. This provides a framework in which the SIGW spectrum fixes the signal band, while higher-order statistics probe residual coherence beyond the power spectrum.
ER -