{
  "abstract": "The start of the Legacy Survey of Space and Time marks a new era for strong lensing science, where the number of strong lenses identified is expected to increase to $\\mathcal{O}(10^5)$. In this paper we use a neural network to determine the precision with which lens parameters can be determined, using realistic simulated LSST lensed systems. We find that the Einstein radius can be measured with a mean precision of $3.7\\%$ with calibrated uncertainties accurately reflecting the corresponding measurement error. Based on the performance of current strong lens classifiers, the $\\sim 100,000$ detectable strong lenses are expected to be accompanied by a similar or larger number of false positives (non-lenses). In readiness for this we introduce a formalism, termed `COSMIC-BEAMS', to infer cosmological parameters while accounting for contamination by false positives. As a proof-of-concept, using simulated LSST measurements of the Einstein radii of a realistic and impure sample of photometric lens systems, i.e. those without spectroscopic confirmation, we find that the cosmological parameters $Ω_m$, $Ω_Λ$, and $w$ can be measured to a precision of $0.1$, $0.03$ and $0.15$ respectively for a $w$CDM cosmology. We demonstrate that unbiased cosmological parameters can be inferred even in strong lens samples contaminated by $50\\%$ false positives, and that the photometric dataset of $100\\,000$ strong lenses will provide equivalent $w$-precision to $2500-3500$ spectroscopic systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.21699",
  "author_total": 10,
  "authors": [
    {
      "name": "Philip Holloway"
    },
    {
      "name": "Aprajita Verma"
    },
    {
      "name": "Philip J. Marshall"
    },
    {
      "name": "Padmavathi Venkatraman"
    },
    {
      "name": "Sydney Erickson"
    },
    {
      "name": "Tian Li"
    },
    {
      "name": "Simon Birrer"
    },
    {
      "name": "Steven Dillmann"
    },
    {
      "name": "Thomas E. Collett"
    },
    {
      "name": "the LSST Dark Energy Science Collaboration"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/et2yhwswaemxp.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.21699",
  "fulltext_url": null,
  "id": "et2yhwswaemxp",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.21699",
  "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.CO"
    ],
    [
      "arxiv",
      "astro-ph.GA"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.21699",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-18",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/et2yhwswaemxp.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:03Z",
      "native_id": "2609.21699",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.21699"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Lens Modeling and Cosmological Inference from an Impure Sample of Galaxy-Galaxy Strong Lenses",
  "title_text": "Lens Modeling and Cosmological Inference from an Impure Sample of Galaxy-Galaxy Strong Lenses",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:03Z",
  "url": "https://research.draconitic.com/paper/et2yhwswaemxp",
  "venue": "arXiv",
  "versions": []
}