Pith. sign in

REVIEW 7 cited by

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2112.05037 v3 pith:JRDUQLKB submitted 2021-12-09 quant-ph astro-ph.COhep-th

Discord and Decoherence

classification quant-ph astro-ph.COhep-th
keywords quantumdiscordsystemdecoherencestatebelieveddecreaseenvironment
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

In quantum information theory, quantum discord has been proposed as a tool to characterise the presence of "quantum correlations" between the subparts of a given system. Whether a system behaves quantum-mechanically or classically is believed to be impacted by the phenomenon of decoherence, which originates from the unavoidable interaction between this system and an environment. Generically, decoherence is associated with a decrease of the state purity, i.e. a transition from a pure to a mixed state. In this paper, we investigate how quantum discord is modified by this quantum-to-classical transition. This study is carried out on systems described by quadratic Hamiltonians and Gaussian states, with generalised squeezing parameters. A generic parametrisation is also introduced to describe the way the system is partitioned into two subsystems. We find that the evolution of quantum discord in presence of an environment is a competition between the growth of the squeezing amplitude and the decrease of the state purity. In phase space, this corresponds to whether the semi-minor axis of the Wigner ellipse increases or decreases, which has a clear geometrical interpretation. Finally, these considerations are applied to primordial cosmological perturbations, thus allowing us to investigate how large-scale structures in our universe, which are believed to arise from quantum fluctuations, can exhibit classical properties.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 7 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Quantum Stochastic Inflation

    hep-th 2026-06 unverdicted novelty 8.0

    Stochastic inflation emerges as GKLS open-system dynamics from tracing entangled modes entering a coarse-grained de Sitter patch, reproducing the classical phase-space Fokker-Planck equation.

  2. Hidden quantum-informatic symmetries of quasi-de Sitter backgrounds

    hep-th 2026-07 unverdicted novelty 7.0

    Wands-dual quasi-de Sitter backgrounds produce identical symplectic eigenvalues in the Gaussian covariance matrix of localized scalar modes, revealing a quantum-informatic symmetry preserved by the duality's canonical...

  3. Schwinger-Keldysh Path Integral for Gauge theories

    hep-th 2026-04 unverdicted novelty 7.0

    Constructs a manifestly diagonal-BRST-invariant Schwinger-Keldysh path integral for open non-Abelian gauge theories with arbitrary physical initial states, yielding Ward-Takahashi-Slavnov-Taylor identities and a Keldy...

  4. When the Environment Speaks: Quantum Signatures in Non-Attractor Inflation

    astro-ph.CO 2026-07 conditional novelty 6.0

    An open quantum system treatment of curvature perturbations during Ultra-Slow-Roll inflation shows that environmental decoherence erases the interference dip, modifies the growth slope, and induces oscillatory feature...

  5. A Landscape of Cosmological Decoherence

    gr-qc 2026-06 unverdicted novelty 6.0

    A geometric landscape of mixed states for cosmological perturbations unifies decoherence models and derives non-linearity bounds that rule out decohered thermal states and limit amplitude-diagonal models to under 70 e...

  6. Schwinger-Keldysh Path Integral for Gauge theories

    hep-th 2026-04 unverdicted novelty 6.0

    A manifestly BRST-invariant Schwinger-Keldysh path integral is derived for non-Abelian gauge theories with generic initial states, enabling perturbative Ward-Takahashi-Slavnov-Taylor identities and Open EFT expansions...

  7. Gauging Open EFTs from the top down

    hep-th 2025-12 unverdicted novelty 6.0

    Derives gauge-invariant influence functionals for photons and Stueckelberg fields in open U(1) gauge EFTs via BRST on the in-in contour after integrating out matter.