{
  "abstract": "Activity can enhance the long-wavelength density fluctuations of a solid beyond the equilibrium fluctuations predicted by the Mermin-Wagner-Hohenberg theorem, but the microscopic origin of this enhancement remains unclear. We study a two-dimensional active Brownian crystal whose longitudinal and transverse displacement covariances scale as $C^u_λ(q)\\sim q^{-3}$ as compared to the passive counterpart with $q^{-2}$ law. This spectrum predicts an MSD-plateau divergence proportional to $L$ in two dimensions, logarithmic in three dimensions, and finite in four dimensions, in close correspondence with recent results reported in Dey et al. [Nat. Commun. 16, 5498 (2025)]. Inverse of the Covariance gives $H^{\\mathrm{cov}}_λ\\sim |q|^3$ with the corresponding dispersion $ω_{\\mathrm{cov},λ}\\sim q^{3/2}$, whereas direct mechanical response gives $K_{\\mathrm{resp},λ}\\sim q^2$ and acoustic modes with $ω_{0,λ}\\sim q$. The nonlinear dispersion is therefore covariance-defined rather than mechanical. The mobility and integrated active-force correlations remain non-singular, although a finite-persistence crossover cannot be ruled out completely with the existing data. Microscopically, the longitudinal and transverse Irving-Kirkwood interaction-stress spectra scale as $q^{-1}$. The transverse stress-stress correlation connects well with the anomalous displacement field, indicating that activity anomalously populates ordinary acoustic modes, while the conservative interaction network transmits the resulting fluctuations as long-ranged stress. A three-dimensional active FCC crystal exhibits the same paired low-$q$ trends.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.00634",
  "author_total": 2,
  "authors": [
    {
      "name": "Antik Bhattacharya"
    },
    {
      "name": "Smarajit Karmakar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/39swyvjpramfr.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.00634",
  "fulltext_url": null,
  "id": "39swyvjpramfr",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.00634",
  "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.dis-nn"
    ],
    [
      "arxiv",
      "cond-mat.soft"
    ],
    [
      "openalex",
      "3104|Micro and Nano Robotics"
    ]
  ],
  "openalex": "W7216397217",
  "pdf_url": "https://arxiv.org/pdf/2610.00634",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/39swyvjpramfr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:03Z",
      "native_id": "2610.00634",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.00634"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.dis-nn",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Enhanced Long-Wavelength Fluctuations and Interaction-Stress Correlations in Active Crystals",
  "title_text": "Enhanced Long-Wavelength Fluctuations and Interaction-Stress Correlations in Active Crystals",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:03Z",
  "url": "https://research.draconitic.com/paper/39swyvjpramfr",
  "venue": "arXiv",
  "versions": []
}