25.4.14:15

Giulia Codenotti (FU Berlin)

Title: The covering minima of lattice polytopes

Abstract:

The covering minima of a convex body were introduced by Kannan and Lovasz to give a better bound in the flatness theorem, which states that lattice point free convex bodies cannot have arbitrarily large width. These minima are similar in flavor to Minkowski's successive minima, and on the other hand generalize the covering radius of a convex body. I will speak about recent joint work with Francisco Santos and Matthias Schymura, where we investigate extremal values of these covering minima for lattice polytopes.

2.5.14:15

Alexandru Constantinescu (FU Berlin)

9.5.14:15

Michael Cuntz (Univ. Hannover)

Title: Classification of Weyl groupoids

Abstract: Finite Weyl groupoids (these are certain simplicial arrangements in a lattice) were completely classified in a series of papers by Heckenberger and myself. However, this classification is based on two computer proofs checking millions of cases. In this talk, I want to report on recent progress in finding a shorter proof. In particular, we prove without using a computer that, up to equivalence, there are only finitely many irreducible finite Weyl groupoids in each rank greater than two.

16.5.14:15

Volkmar Welker (Philipps-Univ. Marburg)

23.5.14:15

Davide Bolognini (Univ. Bologna)

30.5.14:15

No Seminar (Himmelfahrt)

6.6.14:15

Cesar Ceballos (Univ. Wien)

13.6.14:15

Katharina Jochemko (KTH)

20.6.14:15

Jose Samper (MPI Leipzig)

27.6.14:15

No Seminar (Due to the BGSMath--BMS Joint Meeting)

4.7.14:15

Rekha Thomas (Univ. Washington)

11.7.14:15

Madeline Brandt (Berkeley/Leipzig)