{"paper":{"title":"Outer space for untwisted automorphisms of right-angled Artin groups","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.GT"],"primary_cat":"math.GR","authors_text":"Karen Vogtmann, Nathaniel Stambaugh, Ruth Charney","submitted_at":"2012-12-19T18:58:46Z","abstract_excerpt":"For a right-angled Artin group $A_\\Gamma$, the untwisted outer automorphism group $U(A_\\Gamma)$ is the subgroup of $Out(A_\\Gamma)$ generated by all of the Laurence-Servatius generators except twists (where a {\\em twist} is an automorphisms of the form $v\\mapsto vw$ with $vw=wv$). We define a space $\\Sigma_\\Gamma$ on which $U(A_\\Gamma)$ acts properly and prove that $\\Sigma_\\Gamma$ is contractible, providing a geometric model for $U(A_\\Gamma)$ and its subgroups. We also propose a geometric model for all of $Out(A_\\Gamma)$ defined by allowing more general markings and metrics on points of $\\Sigma"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1212.4791","kind":"arxiv","version":3},"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"}