{
  "abstract": "We present a series of unprecedently long 2D3V PIC simulations of unmagnetized relativistic $e^{-}e^{+}$-pair shocks performed in a front-comoving frame. By implementing a moving-wall boundary condition in the downstream together with continuous injection at the upstream boundary, we maintain a fixed simulation domain size, opening the way to perform substantially longer simulations. Our longest runs extend beyond $100000\\,ω_p^{-1}$, exceeding the duration of the previously published simulations by a factor of several. Across a diverse set of simulations --- varying upstream/downstream lengths, transverse sizes, and particle-per-cell counts --- we find strong evidence that the shock, {modelled for a long-time in the front-comoving frame,} approaches an asymptotic, time-independent state. In the downstream region, the steady state depends only on the upstream temperature at the injection boundary and {remains the same if we change the downstream and upstream lengths.} The upstream precursor evolves slower and retains a dependence on the simulation's upstream length, that may be of minor observational consequence, since radiation from astrophysical shocks predominantly originates from the downstream region. {Our simulations also indicate} that Fermi-type acceleration is limited in energy and a true power-law tail never forms. Another important finding is that the downstream magnetic field has a soliton-like structure, where individual magnetic domains evolve independently, each comprising a compact, highly magnetized core embedded within an extended, weakly magnetized region. The magnetic-field distribution around the centers of these spots has approximately Lorentzian profile.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2607.14235",
  "author_total": 2,
  "authors": [
    {
      "name": "Mikhail Garasev"
    },
    {
      "name": "Evgeny Derishev"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5c3vfwvb1xy9v.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2607.14235",
  "fulltext_url": null,
  "id": "5c3vfwvb1xy9v",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2607.14235",
  "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",
      "astro-ph.HE"
    ],
    [
      "arxiv",
      "physics.plasm-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2607.14235",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5c3vfwvb1xy9v.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2607.14235",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2607.14235"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.plasm-ph",
      "subfield": "plasma"
    }
  ],
  "title": "Ultra-long simulations of collisionless relativistic shocks in front-comoving frame: evidence for a steady state and its properties",
  "title_text": "Ultra-long simulations of collisionless relativistic shocks in front-comoving frame: evidence for a steady state and its properties",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:50Z",
  "url": "https://research.draconitic.com/paper/5c3vfwvb1xy9v",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/3x5z-s4wv",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}