{
  "abstract": "Pedestrians in a crowd largely walk in small groups, dyads above all, and modelling how these groups arrange themselves is a step towards realistic models of the crowd as a whole. A dyad walks side by side in a dilute crowd and one behind the other in a dense one, an abreast to in-file transition recently measured in real life across the full range of naturally occurring crowd conditions (van der Laan and Corbetta, PLOS ONE 2026). The cost-function models of dyad formation by Zanlungo and coworkers (Phys. Rev. E 2014; EPL 2015) hold the pair abreast and have no in-file minimum at any finite density. Building on them, we propose and analyse a qualitative model in which the transition appears as an effective density parameter grows: the two formations become minima that coexist over a window of densities and exchange stability within it. We quantify this transition by computing the Orientation Log-Odds $Π_\\text{OLO}$ as predicted by the model. This paper is a first step towards quantitative models of dyads and of their formation transitions.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.16400",
  "author_total": 3,
  "authors": [
    {
      "name": "Alessandro Corbetta"
    },
    {
      "name": "Chiel van der Laan"
    },
    {
      "name": "Francesco Zanlungo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5mcqg9m908pfg.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.16400",
  "fulltext_url": null,
  "id": "5mcqg9m908pfg",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.16400",
  "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",
      "physics.soc-ph"
    ],
    [
      "openalex",
      "2212|Evacuation and Crowd Dynamics"
    ]
  ],
  "openalex": "W7221813727",
  "pdf_url": "https://arxiv.org/pdf/2610.16400",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-12",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5mcqg9m908pfg.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2610.16400",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.16400"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.soc-ph",
      "subfield": "statistical-nonlinear"
    }
  ],
  "title": "Towards modelling abreast to in-file transitions in small pedestrian groups",
  "title_text": "Towards modelling abreast to in-file transitions in small pedestrian groups",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/5mcqg9m908pfg",
  "venue": "arXiv",
  "versions": []
}