{
  "abstract": "We investigate whether absorption can enhance morphological differences between images of different spacetimes, particularly when their critical impact parameters are similar. Using a phenomenological thick-accretion-flow model with an effective absorption coefficient $χ_0$, we compare Schwarzschild black-hole images with those of Bardeen, Hayward, and Ayón-Beato--García black holes. In the face-on Schwarzschild--Bardeen comparison with $g/M=0.5$, the dominant brightness shifts from a narrow lensed feature to a broader outer feature at $χ_0M\\simeq$0.585 and 0.717, respectively. Near the first transition, the integrated difference between independently normalized images increases by $23.5$% on a common physical grid and by $46.6$% after rescaling by the respective critical impact parameters. Enhancement occurs across all three regular-black-hole families and over a broad range of the sampled flow parameters and viewing inclinations, although its magnitude and occurrence depend on the prescribed flow. Asynchronous brightness-peak transitions alone are insufficient to guarantee enhancement. These results suggest that the opacity dependence of image morphology may provide information complementary to the critical-curve scale, potentially helping distinguish spacetimes with similar characteristic shadow sizes. Assessing this possibility observationally requires physically consistent, frequency-dependent radiative transfer.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.07544",
  "author_total": 3,
  "authors": [
    {
      "name": "Tong Li"
    },
    {
      "name": "Jian-Yun Wan"
    },
    {
      "name": "Zi-Liang Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/35my03639wy9t.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.07544",
  "fulltext_url": null,
  "id": "35my03639wy9t",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.07544",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "gr-qc"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.07544",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/35my03639wy9t.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T18:21:30Z",
      "native_id": "2611.07544",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.07544"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Can absorption enhance differences between black-hole images?",
  "title_text": "Can absorption enhance differences between black-hole images?",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:41Z",
  "url": "https://research.draconitic.com/paper/35my03639wy9t",
  "venue": "arXiv",
  "versions": []
}