Speakers
Lydia Außenhofer
Barbara Baumeister
Ruth Charney
Corina Ciobotaru
Tom De Medts
Amandine Escalier
Ralf Köhl
Norbert Knarr
Alexander Lytchak
Bernhard Mühlherr
Damian Osajda
Petra Schwer
Jeroen Schillewaert
Markus Stroppel
Maneesh Thakur
Anne Thomas
Hendrik Van Maldeghem
Olga Varghese
Richard Weiss
Stefan Witzel
Organisers
Sira Busch,
Corina Ciobotaru,
Siegfried Echterhoff,
Petra Schwer,
Olga Varghese
Schedule
The following is our preliminary schedule:
Time 
Monday, 23.09.24 
Tuesday, 24.09.24 
Wednesday, 25.09.24 
Thursday, 26.09.24 
08:0009:00 

WINTA* Breakfast 


09:0009:30 
Registration 


09:3010:20 
Hendrik Van Maldeghem 
Corina Ciobotaru 
Olga Varghese 
Stefan Witzel 
10:2010:30 
Break 
Break 
Break 
Break 
10:3011:20 
Markus Stroppel 
Lydia Außenhofer 
Richard Weiss 
Alexander Lytchak 
11:2012:00 
Coffee Break 
Coffee Break 
Coffee Break 
Coffee Break 
12:0012:50 
Barbara Baumeister 
Anne Thomas 
Petra Schwer 
Norbert Knarr 
12:5014:30 
Lunch Break 
Lunch Break 
Lunch Break 
Lunch Break 
14:3015:20 
Amandine Escalier 
Ralf Köhl 
Ruth Charney (Colloquium) 
Damian Osajda 
15:2016:00 
Coffee Break 
Coffee Break 
Coffee Break 
End of conference 
16:0016:50 
Bernhard Mühlherr 
Maneesh Thakur 


16:5017:00 
Break 
Break 


17:0017:50 
Tom De Medts 
Jeroen Schillewaert 


18:00... 
Reception / Poster session 



19:00... 


Conference dinner 

*WINTA is an acronym used for women, inter, nonbinary, trans and agender people.
Abstracts
Lydia Aussenhofer
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Barbara Baumeister
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Ruth Charney
Exploring the Mysteries of Artin groups
Abstract: Coxeter groups arise in many areas of mathematics including topology, algebraic geometry, representation theory, and combinatorics. They are much studied and generally wellunderstood. Closely related to Coxeter groups are a class of groups known as Artin groups. The best known examples of these groups are the braid groups. While easy to define, Artin groups are much more mysterious than Coxeter groups with many key properties unknown and basic questions unanswered. In this talk, I will introduce Artin groups, discuss some of the open problems, and survey some recent work, using both combinatorial and geometric methods, to approach these problems.
Corina Ciobotaru
Applications of strongly Iregular hyperbolic elements to affine buildings
Abstract: For a locally finite thick Euclidean buildings X of finite Coxeter system (W, S) and for any subset I of S we define the notion of a strongly Iregular hyperbolic automorphism of X. When I is the empty set one gets the already known notion of strongly regular elements. Although the dynamics of strongly Iregular elements on the spherical building of X is much more complicated than for the strongly regulars ones, we get interesting applications. Namely, we show that for closed groups G with a typepreserving and strongly transitive action by automorphisms on X, the Chabauty limits of certain closed subgroups of G contain as a normal subgroup the entire unipotent radical of concrete parabolic subgroups of G.
Tom De Medts
G_{2} and F_{4}graded Lie algebras and cubic norm structures
Abstract: An element x in a Lie algebra L is called extremal if [x, [x, y]] is a scalar multiple of x, for all y in L. The extremal elements give rise to an extremal geometry, and if the Lie algebra is a simple Lie algebra of an algebraic group, then typically, this extremal geometry is the shadow space of a building. We show that, under some natural conditions on the extremal geometry, the Lie algebra admits a G_{2}grading and can be parametrized by a socalled cubic norm structure. Conversely, from any cubic norm structure, we can construct a G_{2}graded Lie algebra. Moreover, we believe that, for a certain class of cubic norm structures known as Freudenthal algebras, the G_{2}grading can be further refined to an F_{4}grading. This is based on joint work with Jeroen Meulewaeter and with Torben Wiedemann.
Amandine Escalier
Commensurability, measure and orbit equivalence of graph products
Abstract: Graph products form a family of groups generalising both right angled Artin groups and right angled Coxeter groups. In this talk we will study the behaviour of graph products from the point of view of measured dynamics. We will also talk about their classification up to commensurability and highlight the links with geometric group theory. If times permit we will present the main ideas of the proof and discuss the role played by the Davis building. This is joint work with Camille Horbez.
Ralf Köhl
Linus's groundbreacking contributions to topological twin buildings and topological KacMoody groups
Abstract: 2002 Linus published a paper in which he topologizes affine twin buildings. His axioms are so wellchosen that they allow also for a meaningful theory in the indefinite case, as Hartnick, Mars and R.K. have observed. Moreover, it is possible to topologize KacMoody groups via colimit techniques starting out with the Lie group topology on the spherical subgroups, as observed by Glöckner, Hartnick, Mars and R.K; here the BurnsSpatzier theorem enters in a subtle way. Once this is in place, one can study fundamental groups of KacMoody groups (as done by Harring and R.K.) and symmetric spaces for KacMoody groups (as done by Freyn, Horn, Hartnick, Vock and R.K.). In my talk I will outline how Linus' pioneering work on topological (twin) buildings made all this progress possible.
Norbert Knarr
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Alexander Lytchak
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Bernhard Mühlherr
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Damian Osajda
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Petra Schwer
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Jeroen Schillewaert
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Markus Stroppel
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Maneesh Thakur
Embedding rank 2 normic tori in groups of type F_{4}
Abstract: In this talk, we will report on some results on embedding rank 2 normic tori in automorphism groups of Albert algebras. We shall also discuss a new characterisation of Albert algebras that are Tits first constructions. This is work in progress, with Holger Petersson.
Anne Thomas
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Hendrik Van Maldeghem
Lines
Abstract: A line is a basic concept in most of axiomatic geometry. Geometric hyperplanes, on the other hand, are defined using the concept of a line. In this talk we reverse the roles of hyperplanes and lines and review some old and new results that characterise lines in Lie incidence geometries. We present some applications to spherical buildings.
Olga Varghese
The isomorphism problem for Coxeter groups meets profinite rigidity
Abstract: By definition, a group is profinitely rigid if it is determined up to isomorphism by its finite quotients amongst all finitely generated residually finite groups. In this talk I will present recent work with Samuel Corson, Sam Hughes and Philip Möller on the question of profinite rigidity of Coxeter groups. I will also explain how profinite rigidity of Coxeter groups is connected to the isomorphism problem of these groups.
Richard Weiss
Tits hexagons
Abstract: The notion of a Tits polygon generalizes the notion of a Moufang polygon. There is a natural construction that produces Tits polygons from a given spherical building and a matching Tits index. These are the Tits polygons of index type. We will describe ongoing efforts to understand the structure of the Tits hexagons of index type and their associated algebraic structures. This is joint work with Bernhard Mühlherr.
Stefan Witzel
Exotic building lattices
Abstract: Most higherrank euclidean buildings are BruhatTits by the classification by Tits and Weiss, therefore lattices on them are arithmetic by work of Margulis. The exception is in dimension two where many nonarithmetic lattices exist, among them the simple lattices on products of trees found by BurgerMozes. I will speak about efforts to find simple lattices on irreducible buildings. My share of effort is joint with Jean Lécureux and Thomas Titz Mite.
Registration
Please register here to take part in the conference.
Deadline for registration: 23.08.2024
We plan to do a poster session and will send an email regarding contributions to all people, who have registered, after the registration deadline.
Support and child care
Childcare is available free of charge for all conference participants. We will ask for information during registration.
Venue and Travel Information
The conference takes place in room SRZ 216/217 on the second floor of the seminar building (Seminarraumzentrum, SRZ) next to the Faculty of Mathematics and Computer Science and the Cluster of Excellence Mathematics Münster.
University of Münster
Seminarraumzentrum (SRZ)
OrléansRing 12
48149 Münster
Germany
Directions can be found on openstreetmap, on the University of Münster campus map and on the MM websites.
We have also collected practical information in a leaflet: Information for conference guests / Informationsblatt für Tagungsteilnehmer:innen [enIde]
Poster
You are welcome to download the poster from this page and display it at your institution.
Sponsor
The conference is supported by the Cluster of Excellence Mathematics Münster and the Villum Fonden foundation.
Accommodation
Rooms in Münster are booked out far in advance. We recommend to book early and provide a list of possible places to stay:
Haus Niemann
Bentelerstr. 4
48149 Münster
Jugendgästehaus Aasee
Bismarckallee 31
48151 Münster
Nordstern Hostel
Hoyastraße 3
48147 Münster
Ibis Budget Münster
Herwarthstr. 8
48143 Münster
Stadthotel Münster GmbH
Aegidiistr. 21
48143 Münster
Hotel Conti
Berliner Platz 2
48143 Münster