{
  "abstract": "Gravitational microlensing probes unresolved quasar accretion disc structure and compact objects in lens galaxies and is an important systematic in strong-lens time-delay cosmography. Most analyses use static microlensing map simulations because evolving individual microlenses and caustics is computationally prohibitive. We present Microcaustics, a GPU-accelerated Python package built on PyTorch for dynamical microlensing of time-dependent extended sources in strong gravitational lenses. It combines a local-exact/far-field deflection solver, source-directed lens-plane scouting with temporal reuse, and biquadratic inverse polygon mapping (IPM). GPU batching and fused Triton rasterization accelerate the calculation, while binary caustic labels track source-centred crossings. Across three simulated quadruply lensed quasar systems, our package generates a 10-year, 147-frame multiband light curve in an amortized median of 0.68 s (0.88 s with labels) on a consumer GPU with a median light-curve RMSE of 0.35 mmag, while recovering every reference source-centred caustic crossing. At comparable map accuracy, the batched throughput is 780 times higher than that of a recent CUDA IPM implementation and extrapolates to a speedup of millions relative to classic GPU-D. We demonstrate that our IPM converges as $N_{\\rm ray}^{-0.84}$, approaching the idealized $N_{\\rm ray}^{-1}$ convergence rate of piecewise-affine IPM and improving upon the $N_{\\rm ray}^{-1/2}$ inverse ray-shooting rate. We also introduce a GPU-resident general relativistic and reverberating quasar source model and demonstrate our method with an evolving supernova source. These advances make fully dynamical stellar fields practical for Bayesian and simulation-based inference.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.19703",
  "author_total": 10,
  "authors": [
    {
      "name": "Joshua Fagin"
    },
    {
      "name": "Connor Stone"
    },
    {
      "name": "James Hung-Hsu Chan"
    },
    {
      "name": "Sophia Miskiewicz"
    },
    {
      "name": "Henry Best"
    },
    {
      "name": "Paras Sharma"
    },
    {
      "name": "Matthew O'Dowd"
    },
    {
      "name": "Laurence Perreault-Levasseur"
    },
    {
      "name": "Yashar Hezaveh"
    },
    {
      "name": "Simon Birrer"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6ymnxnvdsf3qs.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.19703",
  "fulltext_url": null,
  "id": "6ymnxnvdsf3qs",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.19703",
  "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.GA"
    ],
    [
      "arxiv",
      "astro-ph.IM"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7222098174",
  "pdf_url": "https://arxiv.org/pdf/2610.19703",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6ymnxnvdsf3qs.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2610.19703",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.19703"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    }
  ],
  "title": "Microcaustics: Fast GPU-Accelerated Dynamical Microlensing of Time-Dependent Extended Sources",
  "title_text": "Microcaustics: Fast GPU-Accelerated Dynamical Microlensing of Time-Dependent Extended Sources",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/6ymnxnvdsf3qs",
  "venue": "arXiv",
  "versions": []
}