{
  "abstract": "We present the third release of $\\texttt{ULYSSES}$, a Python package for the numerical evaluation of the baryon asymmetry generated through leptogenesis. This version includes code implementing state-of-the-art density matrix equations for low-scale leptogenesis with three quasi-degenerate right-handed neutrinos. We extend the validity of the code in this scenario beyond the 100 GeV right-handed neutrino mass scale, into the regime of resonant leptogenesis, by including neutrino production rates valid in both the relativistic and non-relativistic regimes. In addition, in the high-scale vanilla scenario, we provide routines for computing $ΔL = 1$ scattering processes, enabling full phase-space evolution of the right-handed neutrino and lepton asymmetry. A new $\\texttt{--extended}$ parameter interface allows users to pass model-specific inputs beyond the standard leptogenesis runcard without modifying the core infrastructure and demonstrate its use with a toy module that simultaneously solves the vanilla leptogenesis equations and the freeze-in production of dark matter. On top of these improvements, we introduce an alternative parametrisation of the Casas-Ibarra matrix, update the default neutrino oscillation parameters and report cross-checks of the new low-scale leptogenesis module against published benchmarks and independent codes. $\\texttt{ULYSSES}$ is publicly available on $\\href{https://github.com/earlyuniverse/ulysses}{\\texttt{GitHub}}$ and pip-installable from PyPI.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Computer Physics Communications, 330 (2027) 110464, ISSN 0010-4655",
  "arxiv": "2605.16540",
  "author_total": 5,
  "authors": [
    {
      "name": "Alessandro Granelli"
    },
    {
      "name": "Juraj Klarić"
    },
    {
      "name": "Dhruv Pasari"
    },
    {
      "name": "Yuber F. Perez-Gonzalez"
    },
    {
      "name": "Jessica Turner"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/77wvtgzmzhhww.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.16540",
  "fulltext_url": null,
  "id": "77wvtgzmzhhww",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.16540",
  "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",
      "hep-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2605.16540",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/77wvtgzmzhhww.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2605.16540",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.16540"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "ULYSSES the Third: An Odyssey Towards a Unified Python Toolkit for Leptogenesis",
  "title_text": "ULYSSES the Third: An Odyssey Towards a Unified Python Toolkit for Leptogenesis",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/77wvtgzmzhhww",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1016/j.cpc.2026.110464",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}