{"paper":{"title":"Accessing the homogeneity scale with 21 cm intensity mapping surveys","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Beam convolution in 21 cm intensity mapping erases the homogeneity scale beyond a redshift-dependent maximum beam width.","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Bruno B. Bizarria, Camila P. Novaes, Carlos A. Wuensche, Felipe Avila, Gabriel A. S. Silva, Helissa H. da Costa, Rahima Mokeddem","submitted_at":"2025-11-17T21:35:07Z","abstract_excerpt":"The homogeneity scale, $R_{\\rm H}$, offers a fundamental test of the Cosmological Principle, yet it has not yet been measured with 21cm intensity mapping surveys. A key limitation for such a measurement is the telescope beam, which artificially smooths the observed signal. We quantify this effect using the two-point correlation function and the correlation dimension, $\\mathcal{D}_2(r)$, to model how beam convolution suppresses intrinsic clustering. For any given redshift $z$, we identify a maximum beam width, $\\sigma_{\\rm max}(z)$, beyond which the homogeneity scale cannot be recovered. This l"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"For any given redshift z, we identify a maximum beam width, σ_max(z), beyond which the homogeneity scale cannot be recovered. This limit defines an inaccessible region in the σ × z parameter space, where R_H is erased by beam smoothing.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The intrinsic clustering signal (before beam convolution) can be accurately modeled using the two-point correlation function and correlation dimension D2(r) such that the suppression effect is cleanly separable from the true homogeneity scale.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Beam convolution in 21cm IM surveys erases the homogeneity scale R_H beyond a redshift-dependent maximum beam width σ_max(z) identified via the correlation dimension D2(r).","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Beam convolution in 21 cm intensity mapping erases the homogeneity scale beyond a redshift-dependent maximum beam width.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"022f6b8fba5364393f0ebb9ceeda2acee5d6a0212b4980a18dbcc96cc9c35049"},"source":{"id":"2511.13931","kind":"arxiv","version":2},"verdict":{"id":"e5c50eb6-b241-470f-8a3b-800a41e2e1ff","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-17T20:12:03.528192Z","strongest_claim":"For any given redshift z, we identify a maximum beam width, σ_max(z), beyond which the homogeneity scale cannot be recovered. This limit defines an inaccessible region in the σ × z parameter space, where R_H is erased by beam smoothing.","one_line_summary":"Beam convolution in 21cm IM surveys erases the homogeneity scale R_H beyond a redshift-dependent maximum beam width σ_max(z) identified via the correlation dimension D2(r).","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The intrinsic clustering signal (before beam convolution) can be accurately modeled using the two-point correlation function and correlation dimension D2(r) such that the suppression effect is cleanly separable from the true homogeneity scale.","pith_extraction_headline":"Beam convolution in 21 cm intensity mapping erases the homogeneity scale beyond a redshift-dependent maximum beam width."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2511.13931/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}