{
  "abstract": "Infrared divergences in QED cancel in inclusive observables through the Bloch--Nordsieck and KLN mechanisms. However, this cancellation removes only the unphysical infrared regulator. The detector resolution scale $ω_{\\max}$, which specifies the maximum energy of unresolved soft photons, remains in the observable cross section. We emphasize that this surviving scale has a natural interpretation as a coarse-graining scale in the reduced density matrix of the hard sector. Soft photons below $ω_{\\max}$ are not observed and are effectively traced over. The corresponding soft-sector overlap therefore becomes resolution dependent, $D_{ij}=D_{ij}(ω_{\\max})$. Observable infrared memory is consequently defined not only by the asymptotic soft sector itself, but also by the resolution scale separating observed and unobserved infrared degrees of freedom. This provides a bridge between the traditional infrared-safe cross-section formulation and the modern interpretation of soft photons as carriers of infrared memory and quantum information.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.08879",
  "author_total": 1,
  "authors": [
    {
      "name": "Takeshi Fukuyama"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0vp25a5vab275.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.08879",
  "fulltext_url": null,
  "id": "0vp25a5vab275",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.08879",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "hep-th"
    ],
    [
      "openalex",
      "3107|Quantum and Classical Electrodynamics"
    ]
  ],
  "openalex": "W7164000372",
  "pdf_url": "https://arxiv.org/pdf/2606.08879",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0vp25a5vab275.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2606.08879",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.08879"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Detector Resolution and Observable Infrared Memory in QED",
  "title_text": "Detector Resolution and Observable Infrared Memory in QED",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/0vp25a5vab275",
  "venue": "arXiv",
  "versions": []
}