{"paper":{"title":"Probing fundamental constant evolution with neutral atomic gas lines","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"2), Canada), India; (2) National Radio Astronomy Observatory, J. N. Chengalur (1) ((1) National Centre for Radio Astrophysics, J. X. Prochaska (3), N. Kanekar (1, S. L. Ellison (4), USA; (3) UCO/Lick Observatory, USA; (4) University of Victoria","submitted_at":"2010-03-01T23:43:20Z","abstract_excerpt":"We have detected narrow HI 21cm and CI absorption at $z \\sim 1.4 - 1.6$ towards Q0458$-$020 and Q2337$-$011, and use these lines to test for possible changes in the fine structure constant $\\alpha$, the proton-electron mass ratio $\\mu$, and the proton gyromagnetic ratio $g_p$. A comparison between the HI 21cm and CI line redshifts yields $\\Delta X/X = [+6.8 \\pm 1.0] \\times 10^{-6}$ over $0 < <z> \\le 1.46$, where $X = g_p \\alpha^2/\\mu$, and the errors are purely statistical, from the gaussian fits. The simple line profiles and the high sensitivity of the spectra imply that statistical errors in"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1003.0444","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}