Retreat 2022 of the SFB-TRR 195

The first retreat of the scond period of the SFB-TRR 195 takes place from Tuesday, 22nd to Friday, 25th March, in the Ebernburg in Bad Münster am Stein. The organisors are Claus Fieker (OSCAR program part), Max Horn (OSCAR program part), Gunter Malle (General program) and Michael Kunte (Organisation).


The main intention is to strengthen cooperation within SFB-TRR 195. Therefore, there will only be very few plenary lectures, instead all mathematical and all software focuses should be given enough opportunity to retreat and work together. In addition, there will be overview lectures for each mathematical focus and dedicated workshops concerning the OSCAR project.  The overview lectures will show the status of the respective subprojects and their general embedding.



Talk No.FieldTitleSpeaker
IGroup and representation theorysurvey talk / presentationMeinolf Geck and Frank Lübeck
IINumber theoryTowards an Atlas of Orthogonal DiscriminantsThomas Breuer
IIINon-commutative algebra and free probability theoryInto the non-commutative: Topological Recursion Meets Free Probability Roland Speicher
IVTropical and polyhedral geometryTropical curvesDan Corey
VAlgebraic GeometryOn the computation of Cox rings of minimal models of symplectic linear quotients Johannes Schmitt


  • Thomas Breuer’s talk: We report about the current status of and the methods used in the computation of the orthogonal discriminants
    of absolutely irreducible orthogonal representations of even degree that are tabulated in the Atlas of Brauer Characters and the Atlas of Finite Groups.
  • Roland Speicher’s talk: Besides some general information about the projects in the areas of non-commutative algebra and free probability theory I will report specifically about recent advances in project A14, where some of the main goals (rewriting combinatorial relations between moment and cumulant sequences into functional relations between corresponding generating power series; extension of free probability to higher genus) have recently been reached by the joint efforts of Gaëtan Borot, Séverin Charbonnier, Elba Garcia-Failde, Felix Leid, Sergey Shadrin.
  • Dan Corey’s talk: I will give an overview of abstract tropical curves and their relation to degenerating families of algebraic curves. Then I will discuss Jacobians of tropical curves, the tropical Torelli theorem of Caporaso-Viviani and Su-Wagner, and tropical curves of hyperelliptic type. Time permitting, I will report on recent work (with Jordan Ellenberg and Wanlin Li) related to the Ceresa cycle and its tropical manifestation.
  • Johnnes’ talk: For a finite symplectic reflection group G over the complex numbers acting on a vector space V, we are interested in a minimal model of the linear quotient V/G.
    We describe an algorithm by Yamagishi (2018) for the computation of the Cox ring of this minimal model which does not require prior knowledge of the minimal model.
    We remark on our current work of implementing this algorithm in OSCAR.


TimeTuesday 22nd MarWednesday 23rd MarThursday 24th MarFriday 25st Mar
9:00-9:30Talk I Talk IIIPresentation additional projects
9:30-10:00 Talk I Talk IIIUnconscious Bias Talk
10:00-10:30Coffee breakCoffee breakUnconscious Bias Talk
10:30-12:30Group WorkGroup workCoffee break / Talk V /
Group work
13:30-14:00Welcome and Introducing new PI Talk II Talk IV
14:00-14:30Planing the group workTalk II Talk IV
14:30-15:00Group workCoffee breakGroup work
15:00-15:30Group workHiking TourGroup work
15:30-16:00Coffee BreakHiking TourCoffee break
16:00-18:00Group workHiking TourGroup work
19:00Wine tastingSteering Committee Meeting

We start at Tuesday, 22nd Mar, at 13:30, with the presentations at the Martin-Luther-Saal. The retreat ends after lunch on Friday, 25th. Here is a printable programm.

Confirmed Participants


Firoozeh Aga
Mara Belotti
Janko Böhm
Thomas Breuer
Daniel Corey
Claus Fieker
Anne Frühbis-Krüger
Jeroen Hanselmann
Jonas Hetz
Max Horn
Birte Johansson
Michael Joswig
Manuel Kany
Lars Kastner
Pascal Kattler
Michael Kunte
Gunter Malle
Hannah Markwig
Dario Mathiä
Stevell Muller
Daniel Rademacher
Friedrich Rober
Daniel Robertz
Alexander Rogovskyy
Julien Schanz
Victoria Schleis
Johannes Schmitt
Daniel Schulz
Pascal Schweitzer
Roland Speicher
Mima Stanojkovski
Christian Steinhart
Ulrich Thiel
Erec Thorn
Davide Cesare Veniani
Laura Voggesberger
Gabriela Weitze-Schmithüsen
Frederik Witt
Matthias Zach


The registration deadline has expired.


The Ebernburg in Bad Münster am Stein can be easily reached by train (train station “Bad Münster am Stein”) or car from all main locations.


We follow the current regulations on the corona pandemic in Rhineland-Palatinate. Moreover we follow the 2G+-Regulation. This means that the retreat is only accessible to vaccinated and recovered people who have current negative rapid tests. The rapid test can be replaced by a recent booster vaccination. If you have cold symptoms, please refrain from participating.