{
  "abstract": "Flocking results from dynamical alignment among neighbors in a collection of active self-propelling objects. The intervening medium, typically a fluid, however, is not considered to be important for alignment, except for acting as a momentum sink. The flocking system is therefore described as momentum nonconserving \"dry\" active matter. Here we investigate a confined system of self-propelled Marangoni swimmers where feedback from the fluid medium, which crucially depends on the shape of the swimmers, influences their alignment. Using up to thirty partially camphor-coated triangular paper boats as polar swimmers, we uncover a disorder-to-order transition, and an unusual re-entrant order-to-disorder transition, as functions of camphor concentration and swimmer density, respectively. We reproduce these transitions by formulating a reaction-diffusion model for the camphor field, coupled to the swimmer dynamics, where propulsion forces arise from surface tension gradients. The shape-dependent hydrodynamic interaction discussed here could be central to efficient flocking in living organisms too.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.10709",
  "author_total": 6,
  "authors": [
    {
      "name": "Abhishek Thakur"
    },
    {
      "name": "Taniya Khatun"
    },
    {
      "name": "Soumyadeep Kundu"
    },
    {
      "name": "Nitin Kumar"
    },
    {
      "name": "P. Parmananda"
    },
    {
      "name": "Anirban Sain"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/da1gn9enw7fxc.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.10709",
  "fulltext_url": null,
  "id": "da1gn9enw7fxc",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.10709",
  "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",
      "cond-mat.soft"
    ],
    [
      "openalex",
      "3104|Micro and Nano Robotics"
    ]
  ],
  "openalex": "W7221072456",
  "pdf_url": "https://arxiv.org/pdf/2610.10709",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/da1gn9enw7fxc.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.10709",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.10709"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.soft",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Beyond Dry Flocking: Shape-Dependent Hydrodynamic Alignment",
  "title_text": "Beyond Dry Flocking: Shape-Dependent Hydrodynamic Alignment",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/da1gn9enw7fxc",
  "venue": "arXiv",
  "versions": []
}