Séminaire Lotharingien de Combinatoire, B90pref (2023), 1 p.

Christian Stump

Preface

The 90th meeting of the Séminaire Lotharingien de Combinatoire took place from September 3 to September 6, 2023, for the third time at the beautiful Evangelische Akademie in Bad Boll (Germany) at the foot of the Schwäbischen Alb. We enjoyed three days of "Kaiserwetter" ("emperor's weather"), with a blue sky and pleasantly gentle evenings.

Our previous meeting two years ago which was still strongly influenced by the Corona pandemic, so we particularly enjoyed a completely normal (and thus enjoyful) Séminaire without any disruptive events.

We had two remarkable lecture series:

Ilse FISCHER (Universität Wien) presented the beautiful and fascinating world of "Alternating sign matrices, alternating sign arrays, and plane partitions". After learning about the history of the discussed structures, we were introduced to make strands of current research in the area.
Bertrand EYNARD (Université Paris-Saclay) used our Bochum chalk boards to introduce us to the "Combinatorics of Ising model maps" and the use of algebraic geometry techniques in enumerative combinatorics. The combination of multi-parameter generating functions on the boards together with enlightening examples on screen made the topic particularly accessible.

The topics of the contributed talks are detailed in the list below and, particularly important, included several young participants who gave their first in-person presentations of their interesting work.

We very much enjoyed the atmosphere: some were walking through the hilly surroundings (or to the Italian ice cream place in town), some were playing soccer, some played billard or table football (aka foosball) at night, and many were sitting together outside in the evenings and enjoyed the meeting.