{"paper":{"title":"Affine extensions of principal additive bundles over a punctured surface","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.AG","authors_text":"Isac Hed\\'en","submitted_at":"2014-07-29T06:29:54Z","abstract_excerpt":"The aim of this article is to make a first step towards the classification of complex normal affine $\\mathbb G_a$-threefolds $X$. We consider the case where the restriction of the quotient morphism $\\pi\\colon X\\to S$ to $\\pi^{-1}(S_*)$, where $S_*$ denotes the complement of some regular closed point in $S$, is a principal $\\mathbb G_a$-bundle. The variety $\\mathrm{SL}_2$ will be of special interest and a source of many examples. It has a natural right $\\mathbb G_a$-action such that the quotient morphism $\\mathrm{SL}_2\\to\\mathbb A^2$ restricts to a principal $\\mathbb G_a$-bundle over the punctu"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1407.7638","kind":"arxiv","version":2},"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"}