Activities recorded since 2000

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Upcoming events (organisation or active participation) MY FAREWELL LECTURE, Ruth Kellerhals, University of Fribourg, 29 November 2024, 16:30h; Campus Pérolles, Departement of Chemistry, PER 10 Lecture Hall 0.013, followed by an Apéro riche at 17:30h: Conferral of an honorary doctorate of the Faculty of Science and Mathematics of the University of Fribourg to Prof. Günter M. Ziegler (FU Berlin), Fribourg, 15 November 2024 10th Plancherel Lecture, Günter M. Ziegler (FU Berlin), Fribourg, 15 November 2024 "Groups in Madrid 2024", ICMAT Madrid, 17 - 18 October 2024; invited speaker Geometry Seminar, EPF Lausanne, 9 October 2024; invited speaker Workshop "Journées de Géométrie hyperbolique", University of Fribourg, 12 - 13 September 2024; conducted together with Naomi Bredon; main organiser Workshop on Explicit Methods in Number Theory, Oberwolfach, 1 - 6 September 2024 Research stay (host Prof. Yohei Komori), Waseda University, 1 week, January 2024 Research Seminars Oberseminar Geometrie, 2006 - 2024 Graduate Seminar on Geometry, Andreas Bernig, Bruno Colbois, Ruth Kellerhals, Bern 2004 - 2006 Oberseminar Geometrie, Ruth Kellerhals, Thomas Zehrt, Fribourg 2000 - 2004 Events (organisation or active participation) "Leonardo Math Camp" for talented high school pupils, Les Diablerets (Switzerland), 11 - 14 October 2023; conducted together with Matthieu Jacquemet (HES Sion / UniFR), Livio Liechti (UniFR) and Damaris Meier (UniFR); main organiser Workshop "Polylogarithms, Cluster Algebras, and Scattering Amplitudes", University of Maryland (U.S.A.), 11 - 15 September 2023; invited speaker Borel Seminar "Lattices in Negative Curvature", in honor of John Parker , Les Diablerets (Switzerland), 17 - 21 July 2023; conducted together with Martin Deraux (Grenoble) and Vincent Emery (BFH Biel); main organiser and speaker Geometry Seminar, Waseda University, 20 January 2023; invited speaker Conference on geometry, arithmetic and dynamics of discrete groups, Moscow Institute of Physics and Technology, Dolgoprudny, 12 - 16 December 2022; invited participant - participation cancelled due to the war of Russia against Ukraine TecDay (SATW), Modul "Dreiecke mit Winkelsumme null?", Kantonsschule Olten, 01.12.2022 Conference "Complex Hyperbolic geometry and related topics", in honor of Elisha Falbel , CIRM, Luminy, July 4 - 8 2022; invited speaker "Zwischenräume", Ludwig Schläfli und höherdimensionale Geometrie, Vortrag und Gespräch mit Pfarrer Erich Wyss, musikalische Begleitung durch den Jugendchor, Reformierte Kirche Meilen, 22.06.2022 Conference "The pursuit of symmetry: A conference in honour of the 80th birthday of Robert V. Moody", The Fields Institute for Research in Mathematical Sciences, Toronto, April 25 - 29, 2022; invited participant TecDay (SATW), Modul "Dreiecke mit Winkelsumme null?", Alte Kantonsschule Aarau, 01.03.2022 Workshop on "Arithmetic reflection groups and crystallographic packings", American Institute of Mathematics AIM, San Jose, March 7 - 11, 2022; invited participant - participation cancelled COGENT Seminar, October 25, 2021, invited speaker; online seminar organised by Philippe Elbaz-Vincent, Graham Ellis, Paul Gunnells and Haluk Sengun Workshop "Lattices and Cohomology of Arithmetic Groups: Geometric and Computational Viewpoints", (online) Banff International Research Station for Mathematical Innovation and Discovery (BIRS), October 3 - 8, 2021; invited participant Special Geometry Seminar, speakers Brent Everitt (York University) and John Parker (Durham University), University of Fribourg, October 6, 2021; organiser Workshop on "Arithmetic reflection groups and crystallographic packings", American Institute of Mathematics AIM, San Jose, March 17 - 23, 2020; invited speaker; postponed to December 14 - 18, 2020, realisation as online workshop Conference on "Symmetries of discrete objects", Rotorua, New Zealand, February 10 - 14, 2020; invited participant, speaker 8th Plancherel Lecture, Andreas Thom (TU Dresden), Fribourg, December 9, 2019 MatheFest 2019, special event, University of Fribourg, September 14, 2019; principal speaker Prof. Günter M. Ziegler (FU Berlin); main organiser Interactions between Hyperbolic Geometry and Number Theory, Conference, University of Luxemburg, July 4 - 5, 2019; invited speaker Géométrie, topologie et arithmétique de façon hyperbolique, Summer School organised by Proffs. V. Emery (UniBE) and A. Kolpakov (UniNE), CUSO Swiss Doctoral Program in Mathematics, Les Diablerets, June 24 - 28, 2019; invited speaker Groups and Geometry Days, Annual Meeting 2019 of the SMS, University of Neuchâtel, June 12 - 14, 2019; invited speaker Mini-Workshop: Reflection Groups in Negative Curvature, organised by Proffs. M. Belolipetsky (IMPA), V. Emery (UniBE) and R. Kellerhals (UniFR), Oberwolfach, April 8 - 13, 2019 Cohomology of Arithmetic Groups, Lattices and Number Theory: Geometric and Computational Viewpoint, CIRM Marseille, March 25 - 29, 2019; invited speaker Topology of Manifolds: interactions between high and low dimensions, Matrix Creswick, University of Melbourne, January 7 - 18, 2019; invited participant Research stay, hosted by Proffs. Stephan Tillmann and Anne Thomas, University of Sydney, 2 weeks January, 2019 Geometry Seminar, Waseda University, November 16, 2018; invited speaker PhD thesis defense of Tomoshige Yukita, 15 November, 2018, Waseda University; external expert Growth in Topology and Number Theory: Volumes, Entropy, and L2-torsion, Hausdorff Center of Mathematics HCM Bonn, July 9 - 13, 2018; organisers: Stefan Friedl (Regensburg), Eriko Hironaka (Florida), Ruth Kellerhals (Fribourg), Wolfgang Lück (Bonn) Computational Challenges in the Theory of Lattices, ICERM, Providence (RI), April 23 - 27, 2018; invited participant TecDay (SATW), Modul "Dreiecke mit Winkelsumme null?", Gymnasium Thun, 21.03.2018 Conference in honor of Christophe Bavard, November 20 - 24, 2017, University of Bordeaux; invited speaker Borel Seminar "Growth in Geometry and Topology", August 2017, Les Diablerets (Switzerland); conducted together with Vincent Emery (Bern), Roman Sauer (KIT Karlsruhe), Stefan Wenger (Fribourg); main organiser Workshop on "Hyperbolic Geometry Beyond Dimension Three", American Institute of Mathematics AIM SQuaRE, San Jose, July 17 - 23, 2017; invited participant Conference "Women in Geometry and Topology", ETH Zürich, June 12 - 16, 2017; invited speaker XXIII Rolf Nevanlinna Colloquium, Zürich, June 12 - 17, 2017; member Nevanlinna Board (together with Kari Astala (University of Helsinki), Pekka Koskela (Jyväskylä), Eero Saksman (University of Helsinki); Zoltan Balogh (Bern), Urs Lang (ETH Zürich); Toshiyuki Sugawa (Tohoku)) Invited researcher, ICTP Trieste, May 12 - June 2, 2017 Guest Senior researcher and invited speaker for the Workshop "Growth 4", Waseda Institute for Advanced Study (WIAS), Waseda University, April 2017 Journées de Géométrie Hyperbolique 2017, Workshop, University of Fribourg, March 23 - 24, 2017; speakers are Martin Deraux (Grenoble), Edoardo Dotti (Fribourg), Simon Drewitz (Fribourg; tbc), Vincent Emery (Bern), Anna Felikson (Durham), Michihiko Fujii (Okinawa), Rafael Guglielmetti (Fribourg), Ann Kiefer (Bielefeld), Olivier Mila (Bern) Workshop on "Discrete Geometry", University of Auckland, February 15 - 16, 2017; invited speaker Workshop on "Hyperbolic Geometry Beyond Dimension Three", American Institute of Mathematics AIM SQuaRE, San Jose, July 18 - 22, 2016; invited participant Workshop Growth 3, Waseda University, Tokyo March 31 - April 1, 2016; invited speaker TecDay (SATW), Modul "Dreiecke mit Winkelsumme null?", Bündner Kantonsschule, Chur, 26.02.2016 Conference on Symmetries and Covers of Discrete Objects, Queenstown, New Zealand, February 14 - 19, 2016; invited speaker Mitteldeutsche Geometrietage, Universität Jena, December 4 - 5, 2015; invited speaker Journées de Géométrie Hyperbolique 2015, Workshop, University of Fribourg, October 15 - 16, 2015; ; speakers are Vincent Emery (Bern), Jordane Granier (Fribourg), Rafael Guglielmetti (Fribourg), John Parker (Durham), John Ratcliffe (Vanderbilt), Pavel Tumarkin (Durham) Workshop on The Geometry, Algebra and Analysis of Algebraic Numbers, BIRS Banff, October 3 - 9, 2015; invited speaker; cancelled Workshop on Geometry of Discrete Actions, ICTP Trieste, August 31 - September 4, 2015; invited speaker Workshop on "Hyperbolic Geometry Beyond Dimension Three", American Institute of Mathematics AIM SQuaRE, San Jose, July 20 - 24, 2015; invited participant Workshop on Discrete Groups and Hyperbolic Geometry, RIMS Kyoto, June 22 - 26, 2015; invited speaker "A duecento anni dalla nascita de L. Schläfli e a duemilatrecento da quella di Archimede", Convegno CMSI, Locarno, October 3 - 4, 2014; invited speaker Workshop on Low-Dimensional Topology and Number Theory, Oberwolfach, August 17 - 23, 2014; invited speaker "Topics in Negative Curvature", a conference in honour of the 70th birthday of Hans-Christoph Im Hof; 4 - 5 August 2014, Mathematical Institute, University of Basel (Switzerland); speakers : C. Bavard (Bordeaux), P. Buser (EPF Lausanne), K. Grove (Notre Dame), J. Ratcliffe (Vanderbilt), P. Tumarkin (Durham), E. Vinberg (Moscow); organiser : R. Kellerhals (Fribourg); click here for the poster Borel Seminar "Discrete Group Actions in Geometry and Topology", 30 June - 4 July 2014, Les Diablerets (Switzerland); co-organiser together with Michelle Bucher (Geneva) and John Parker (Durham); click here for the poster Mini Workshop "Growth2", OCAMI, Osaka City University, February 3 - 4, 2014; invited speaker PhD thesis defense of Yuriko Umemoto, 30 January, 2014, OCAMI, Osaka City University; external expert Geometric Topology Seminar, Mathematical Institute, University of Bonn, 14 January, 2014; invited speaker TecDay (SATW), Modul D10 "Dreiecke mit Winkelsumme null?", Collège St. Michel, Fribourg, 20.11.2013 5th Plancherel Lecture, Alex Lubotzky (Hebrew University Jerusalem), Fribourg 2013 Exotic Geometric Structures, Workshop at ICERM, Brown University, 15 - 20 September, 2013; invited speaker XXII Rolf Nevanlinna Colloquium, Helsinki, August 5 - 9, 2013; member Scientific Committee and Nevanlinna Board Growth and Mahler measures in geometry and topology, Workshop at the Institut Mittag-Leffler, 1 - 5 July, 2013; Djursholm, Sweden; co-organiser together with Eriko Hironaka (Tallahassee); click here, for the IML preprint or here to download the pdf file; and click here for some photos North British Geometric Group Theory Seminar, Durham, 20.06.2013; invited speaker 31. Basler Kolloquium für Mathematiklehrpersonen, Basel, 28.11.2012; invited speaker Journées de Géométrie Hyperbolique 2012, Workshop, Fribourg, 20 - 21 November 2012; click here for the Poster Workshop on Low-Dimensional Topology and Number Theory, Oberwolfach, August 26-September 1, 2012; invited speaker Workshop on Lie groups and algebraic groups, Bielefeld, July 23-25, 2012; invited speaker Geometric and Analytic Aspects of Group Theory, Institut Mittag-Leffler, January 16 - May 30, 2012; invited participant Mini Workshop on Growth, OCAMI, Osaka City University, February 21 - 22, 2012; co-organiser and speaker Conference on Symmetries of Discrete Objects and MAGMA Workshop, Queenstown (New Zealand), February 13 - 17, 2012; invited speaker Borel Seminar "Topics in Real and Complex Hyperbolic Geometry", 22 - 26 August 2011, Les Diablerets (Switzerland); conducted together with Michelle Bucher (Geneva), Elisha Falbel (Paris), John Parker (Durham) IMU General Assembly, 16-17 August 2010, Bangalore (India) The Second W. Killing and K. Weierstrass Colloquium, 24-26 March 2010, Braniewo (Poland) Hyperbolic Geometry and Coxeter Groups, OCAMI Lecture Series 2010, Osaka City University XXI Rolf Nevanlinna Colloquium, Kyoto 2009 14th Meeting European Women in Mathematics EWM, Novi Sad 2009 Swiss Knots 2009, Fribourg 2009 Summer School on Bounded Cohomology, Coxeter Groups and Hyperbolic Geometry, Fribourg 2008 Kovalevskaya Lecture, BMS School of Mathematics, Berlin 2008 Workshop Hyperbolic Volume 2007, Fribourg 2007 XXth Rolf Nevanlinna Colloquium, EPF Lausanne 2005 Spaces of Negative Curvature, Bernoulli Center EPF Lausanne, Program 1 July - 31 December 2005 1st Plancherel Lecture, Don Zagier (MPI Mathematik Bonn), Fribourg 2005 Spring Meeting of the Swiss Mathematical Society on Analysis on Manifolds, Fribourg 2004 Conference on Aspects of Hyperbolic Geometry, Fribourg 2001

Talks

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• Click here for the list of all talks presented by the members of the research group from October 2000 to September 2016