Pith. sign in

REVIEW 7 cited by

Ghostly interactions in (1+1) dimensional classical field theory

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 2504.11437 v1 pith:E77AVWYR submitted 2025-04-15 hep-th gr-qc

Ghostly interactions in (1+1) dimensional classical field theory

classification hep-th gr-qc
keywords classicalinstabilitydemonstratefieldsfluctuationsfrequencyghostlymodes
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

We investigate the classical stability of two coupled scalar fields with opposite-sign kinetic terms evolving in 1+1 dimensional Minkowski spacetime. In the first part, we characterise unquenched ghostly interactions and present numerical solutions that support the following statements. First, the classical instability is not instantaneous and can even be benign, i.e., free of finite-time singularities. Second, while the classical instability can cascade towards higher frequency excitations, it is not driven by high frequency modes: At fixed amplitude, high-frequency modes are more stable than low-frequency modes. In the second part, we demonstrate that the classical instability can be quenched by mass terms. In particular, we exemplify that heavy high-frequency ghost fields seem to not violate the decoupling theorem and can be integrated out classically. In the third part, we demonstrate how self-interactions can quench the instability, for instance, by postponing its onset to parametrically large times. Extrapolating numerical results at large but finite evolution time to infinite evolution time, we demonstrate that classical fluctuations around trivial and nontrivial field-theory vacua are increasingly long-lived with (i) smaller initial amplitude of fluctuations, (ii) higher initial frequency of fluctuations, (iii) larger masses of the fields, or (iv) weaker interaction coupling. Moreover, our numerical simulations for field-theoretical generalisations of some globally-stable ghostly mechanical models do not feature any instability.

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. Ghost Degrees of Freedom Without Quantum Runaway: Exact Moment Bounds from an Operator Conservation Law

    quant-ph 2026-04 unverdicted novelty 7.0

    An exact operator conservation law from canonical commutation relations bounds second moments of a ghost-coupled oscillator for all time and states, preventing quantum runaway.

  2. Effective geometrodynamics for renormalization-group improved black-hole spacetimes in spherical symmetry

    gr-qc 2026-01 unverdicted novelty 7.0

    RG-improved black hole spacetimes with scale-dependent gravitational coupling are derived as vacuum solutions to 2D Horndeski master field equations, embedding prior works and exposing implementation discrepancies.

  3. Quantum mechanics with a ghost: Counterexamples to spectral denseness

    hep-th 2026-04 unverdicted novelty 6.0

    Ghostly quantum systems can have discrete non-dense energy spectra under classical stability conditions, providing counterexamples to spectral denseness.

  4. Unitary Time Evolution and Vacuum for a Quantum Stable Ghost

    hep-th 2026-04 unverdicted novelty 6.0

    A quantum ghost coupled polynomially to a harmonic oscillator has unitary evolution and a stable vacuum because a conserved quantity possesses a positive discrete spectrum.

  5. Physical nonviability of $f(\mathbb{Q})$ in the scalar-tensor representation

    gr-qc 2026-06 unverdicted novelty 2.0

    f(Q) gravity exhibits pathological behavior in its scalar-tensor representation.

  6. Vector modes in Type 3 New GR

    gr-qc 2026-05 unverdicted novelty 2.0

    Substituting constraint equations into the Lagrangian leads to false claims of dynamical vector modes in Type 3 New GR; analysis of the linear equations of motion confirms they are not dynamical.

  7. Vector modes in Type 3 New GR

    gr-qc 2026-05 unverdicted novelty 2.0

    Vector modes in Type 3 New GR are non-dynamical; substituting constraints into the Lagrangian produces incorrect claims of dynamics.