The Faculty of Mathematics hosted this conference about outer space, groups of (outer) automorphisms of free groups and related topics. In addition to the talks, there was a session on open problems in this area. This was one of the accompanying workshops of the 50 Years Faculty of Mathematics Anniversary Conference. The conference took place at Bielefeld University.

If you have questions, please contact the organisers (Benjamin Brück, Kai-Uwe Bux, Dawid Kielak, Stefan Witzel).

This conference is supported by the DFG priority programme 2026 Geometry at Infinity

- Yael Algom-Kfir
- Anthony Genevois
- Funda Gultepe
- Radhika Gupta
- Camille Horbez
- Marek Kaluba
- Catherine Pfaff
- Dionysios Syrigos
- Ric Wade

Time | Title | Speaker |
---|---|---|

Tuesday, 24.09 | ||

10:00 - 11:00 | Rigidity of the Torelli subgroup in Out(F_{n}) | Camille Horbez |

11:30 - 12:30 | Maximal direct products of free groups in Out(F_{N}) | Ric Wade |

14:00 - 15:00 | Typical Trees: An Out(F_{r}) Excursion | Catherine Pfaff |

15:45 - 16:45 | Problem session | |

Wednesday, 25.09 | ||

10:00 - 11:00 | The geometry of hyperbolic free-by-cyclic groups | Yael Algom-Kfir |

11:30 - 12:30 | The Minimally displaced set of an irreducible automorphism is locally finite | Dionysios Syrigos |

14:00 - 15:00 | Homotopy type of the free factor complex | Radhika Gupta |

15:45 - 16:45 | Surface subgroups of Out(F_{n}) via combination of Veech subgroups | Funda Gultepe |

19:00 - 00:00 | Conference Dinner | |

Thursday, 26.09 | ||

10:00 - 11:00 | Aut(F_{n}) has property (T) | Marek Kaluba |

11:30 - 12:30 | Graph products, quasi-median graphs, and automorphisms | Anthony Genevois |

Yael Algom-Kfir

Anthony Genevois

Funda Gultepe

Radhika Gupta

Camille Horbez

Marek Kaluba

Catherine Pfaff

Dionysios Syrigos

Ric Wade

- Algom-Kfir, Yael (
*University of Haifa*) - Beßmann, Lara (
*University of Münster*) - Brück, Benjamin (
*Universität Bielefeld*) - Buran, Michal (
*University of Cambridge*) - Bux, Kai-Uwe (
*Bielefeld University*) - Carstensen, Thomas (
*Christian-Albrechts-Universität, Kiel*) - Flechsig, Jonas (
*Universität Bielefeld*) - Gardam, Giles (
*University of Muenster*) - Genevois, Anthony (
*University Paris-Sud*) - Guerch, Yassine (
*Université Paris-Sud, Laboratoire mathématique d'Orsay*) - Gultepe, Funda (
*University of Toledo*) - Gupta, Radhika (
*Technion*) - Hilmes, Christoph (
*Universität Bielefeld*) - Horbez, Camille (
*CNRS / Université Paris-Sud*) - Kaluba, Marek (
*Adam Mickiewicz University in Poznań/TU Berlin*) - Kielak, Dawid (
*Bielefeld University*) - Martino, Armando (
*Southampton*) - Millard, Ben (
*University College London*) - Möller, Philip (
*University of Muenster*) - Neaime, Georges (
*Universität Bielefeld*) - Pfaff, Catherine (
*University of California, Santa Barbara*) - Santos Rego, Yuri (
*OvGU Magdeburg*) - Syrigos, Dionysios (
*University of Southampton*) - Tielker, Elena (
*Universität Bielefeld*) - Varghese, Olga (
*University of Münster*) - Wade, Ric (
*University of Oxford*) - Witzel, Stefan (
*Bielefeld University*) - Wu, Xiaolei (
*University of Bonn*)