91307 doi 10.5565/PUBLMAT_56212_03 articleid 02141493v56n2p305 eng Fossas, A. Thompson’s group is the orientation-preserving automorphism group of a cellular complex We consider a planar surface ∑ of in nite type which has Thompson's group T as asymptotic mapping class group. We construct the asymptotic pants complex C of ∑ and prove that the group T acts transitively by automorphisms on it. Finally, we establish that the automorphism group of the complex C is an extension of the Thompson group T by Z=2Z. Anglès Tots els drets reservats http://www.europeana.eu/rights/rr-f/ Article de fons Mapping class groups Ip complex Infinite type surfaces Group actions Thompson's groups info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Nguyen, M. Vol. 56, Núm. 2 (2012), p. 0305-326 Publicacions matemàtiques 0214-1493 22 661723 http://ddd.uab.cat/uab/pubmat/pubmat_a2012v56n2/pubmat_a2012v56n2p305.pdf 0305 326 2 56 pubmat_a2012v56n2 2012 ARTPUB PUBMAT UAB artpubuab oai:ddd.uab.cat:91307 driver