eprintid: 32000 rev_number: 13 eprint_status: archive userid: 6843 dir: disk0/00/03/20/00 datestamp: 2022-08-08 10:40:56 lastmod: 2022-08-23 12:21:19 status_changed: 2022-08-08 10:40:56 type: doctoralThesis metadata_visibility: show creators_name: Maret, Arnaud title: The symplectic geometry of surface group representations in genus zero subjects: ddc-500 subjects: ddc-510 divisions: i-110400 adv_faculty: af-11 abstract: We study a compact family of totally elliptic representations of the fundamental group of a punctured sphere into PSL(2,R), discovered by Deroin and Tholozan and named after them. We describe a polygonal model that parametrizes the relative character variety of Deroin–Tholozan representations in terms of chains of triangles in the hyperbolic plane. We extract action-angle coordinates from our polygonal model as geometric quantities associated to chains of triangles. The coordinates give an explicit isomorphism between the space of representations and the complex projective space. We prove that they are almost global Darboux coordinates for the Goldman symplectic form. This work also investigates the dynamics of the mapping class group action on the rela- tive character variety of Deroin–Tholozan representations. We apply symplectic methods developed by Goldman and Xia to prove that the action is ergodic. date: 2022 id_scheme: DOI id_number: 10.11588/heidok.00032000 ppn_swb: 1815007826 own_urn: urn:nbn:de:bsz:16-heidok-320009 date_accepted: 2022-07-22 advisor: HASH(0x55fc36db99d8) language: eng bibsort: MARETARNAUTHESYMPLEC20220725 full_text_status: public place_of_pub: Heidelberg citation: Maret, Arnaud (2022) The symplectic geometry of surface group representations in genus zero. [Dissertation] document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/32000/1/thesis-administration-version.pdf