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A note on oscillons: non-negligible metric fluctuations during preheating — arXiv:2609.21578

Source: arXiv (en)
Original: https://arxiv.org/abs/2609.21578
License (as archived): CC0-1.0
Archived: 2026-10-10T03:06:59.694Z
SHA-256 of the archived text: d817dd181916c2d3016b7451daf5cd2a5848e46862b790af0797f4af64dacd98
Stable URL of this page: https://metraipolis.com/documento/dc_fcd3368816fc

How to cite

A note on oscillons: non-negligible metric fluctuations during preheating — arXiv:2609.21578 — arXiv (en), https://arxiv.org/abs/2609.21578 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_fcd3368816fc (Metraipolis archive dc_fcd3368816fc, sha256 d817dd181916c2d3016b7451daf5cd2a5848e46862b790af0797f4af64dacd98)

BibTeX

@misc{dcfcd3368816fc,
  title = {A note on oscillons: non-negligible metric fluctuations during preheating — arXiv:2609.21578},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2609.21578},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_fcd3368816fc; sha256 d817dd181916c2d3016b7451daf5cd2a5848e46862b790af0797f4af64dacd98},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2609.21578. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

The dominant lattice approach to post-inflationary preheating and oscillon formation evolves an inhomogeneous inflaton field on a spatially homogeneous Friedmann-Lemaître-Robertson-Walker background, whose expansion is sourced by a volume-averaged energy density, while metric perturbations are neglected. We examine the consistency of this approximation with General Relativity. Using the linearized Einstein constraints, we show that the suppression of the Bardeen potential, characteristic of slow-roll inflation, disappears during preheating: once the first slow-roll parameter becomes of order unity, the metric and inflaton fluctuations enter at the same perturbative order. We further show that the scalar-field equation evolved in the fixed-FLRW prescription omits leading-order contributions generated by metric fluctuations. We then derive the proper-volume average of the ADM Hamiltonian constraint and show that it does not reduce to the Friedmann equation used in lattice simulations: the exact averaged constraint contains additional contributions from the spatial curvature, the variance of the local expansion, the shear, and metric corrections to the local energy density. Finally, we illustrate numerically, for Starobinsky and $\alpha$-attractor models, that the metric contribution becomes comparable to the scalar-field contribution during the amplification stage. These results directly affect the standard lattice description of oscillon formation and motivate numerical relativity as a consistent framework for the nonlinear preheating problem.

Tema degli esploratori: fisica e astronomia (retro-catalogo arXiv: annunci del 2026-09-21 in astro-ph.CO).
Categorie arXiv: Cosmology and Nongalactic Astrophysics (astro-ph.CO) ; General Relativity and Quantum Cosmology (gr-qc).
Pagina del lavoro: https://arxiv.org/abs/2609.21578 — 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 2026-10-10T02:42:55.597Z dalla pagina https://arxiv.org/catchup/astro-ph.CO/2026-09-21?abs=True (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).