{
  "abstract": "We present CosmoAgent, an agentic AI framework using large language models (LLMs) to search for dark-energy and modified-gravity models. We define a covariant grammar that allows LLM agents to explore the space of modified-gravity Lagrangians. An in-house computational pipeline derives the equations of motion, solves the background dynamics, and evaluates the likelihood using late-time expansion data, including the DES 5-year type Ia supernova sample and the DESI Data Release 2 BAO measurements. Theories are ranked by the Akaike Information Criterion (AIC) to balance simplicity and likelihood. We benchmarked 8 frontier LLMs from ChatGPT, Claude, Gemini, Kimi, DeepSeek, and Qwen, and all LLMs are able to find theories with a lower nominal AIC than flat $Λ$CDM, with a best improvement of $Δ$ AIC=-3.328. Seven recover quadratic quintessence. Exploratory searches also return induced-gravity and scalar-Gauss-Bonnet structures. The modest AIC improvements do not establish an observational preference for these models over flat $Λ$CDM. The code is publicly available at https://github.com/wsunamoutlook-prog/AI-Modified-Gravity",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.16536",
  "author_total": 5,
  "authors": [
    {
      "name": "Stephon Alexander"
    },
    {
      "name": "Loukas Gouskos"
    },
    {
      "name": "Savvas M. Koushiappas"
    },
    {
      "name": "Cooper Niu"
    },
    {
      "name": "Wenrong Sun"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/924f5jgthynss.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.16536",
  "fulltext_url": null,
  "id": "924f5jgthynss",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.16536",
  "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",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7221792849",
  "pdf_url": "https://arxiv.org/pdf/2610.16536",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/924f5jgthynss.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.16536",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.16536"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "CosmoAgent: AI Agent for Theoretical Cosmology",
  "title_text": "CosmoAgent: AI Agent for Theoretical Cosmology",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/924f5jgthynss",
  "venue": "arXiv",
  "versions": []
}