{
  "abstract": "We formulate an exact density-functional description of the angularly discretized two-dimensional (2D) discrete wormlike chain (DWLC) under tension. The central result is a bond-local closure connecting the nearest-neighbor pair distribution $C_{i,i+1}^{rs}$ to the single-site angular densities $ρ_i^r$: $C_{i,i+1}^{rs}C_{i,i+1}^{00}/(C_{i,i+1}^{r0}C_{i,i+1}^{0s})=e^{\\barβ\\,rs}$, with the bond coupling $\\barβ=βκ\\varepsilon^2/a$. This relation follows directly from the connected Boltzmann weight of the quadratic bending interaction and permits exact integration of the entropy functional. Variational minimization then yields coupled self-consistent equations for the one- and two-site angular distributions, which we solve by fixed-point iteration. We establish the equivalence of this density-functional formulation to the exact transfer-matrix solution: the two approaches reproduce the angular marginals and force-extension curves to machine precision. The formulation also recovers the continuum 2D wormlike-chain behavior, including the rigid-rod and random-coil limits of the mean-square end-to-end distance. Using the segment length and persistence length taken directly from Mazur's short-DNA molecular-dynamics study, without additional fitting, the predicted bend-angle statistics agree with the simulation data within the estimated uncertainty. The closure structure extends naturally to nonharmonic local bending interactions and can also be interpreted inversely, allowing measured nearest-neighbor angular correlations to constrain effective coarse-grained bending potentials. These properties establish a direct connection between conformational statistics and local interactions and provide a density-level framework for treating interacting semiflexible-polymer systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.29743",
  "author_total": 1,
  "authors": [
    {
      "name": "Benaoumeur Bakhti"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2mevxwcjct0vf.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.29743",
  "fulltext_url": null,
  "id": "2mevxwcjct0vf",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.29743",
  "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",
      "cond-mat.soft"
    ],
    [
      "openalex",
      "1606|Advanced Physical and Chemical Molecular Interactions"
    ]
  ],
  "openalex": "W7162800548",
  "pdf_url": "https://arxiv.org/pdf/2605.29743",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2mevxwcjct0vf.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:00Z",
      "native_id": "2605.29743",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.29743"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.soft",
      "subfield": "condensed-matter"
    }
  ],
  "title": "An exact density-functional closure for the two-dimensional discrete wormlike chain",
  "title_text": "An exact density-functional closure for the two-dimensional discrete wormlike chain",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:00Z",
  "url": "https://research.draconitic.com/paper/2mevxwcjct0vf",
  "venue": "arXiv",
  "versions": []
}