Vorträge in der Woche 22.07.2019 bis 28.07.2019

Montag, 22.07.2019: Matroids and their Dressians

Madeline Brandt (UC Berkeley)

In this talk we will explore Dressians of matroids. Dressians have many lives: they parametrize tropical linear spaces, their points induce regular matroid subdivisions of the matroid polytope, they parametrize valuations of a given matroid, and they are a tropical prevariety formed from certain Plücker equations. We show that initial matroids correspond to cells in regular matroid subdivisions of matroid polytopes, and we characterize matroids that do not admit any proper matroid subdivisions. An efficient algorithm for computing Dressians is presented, and its implementation is applied to a range of interesting matroids. If time permits, we will also discuss an ongoing project extending these ideas to flag matroids.

Dienstag, 23.07.2019: Topological Hochschild homology

Dr. Achim Krause (Universität Münster)

Topological Hochschild homology, a refinement of the usual algebraic Hochschild homology, plays an important role in modern computations of algebraic K-theory. In this talk I want to give an introduction to topological Hochschild homology and discuss some recent computations with Thomas Nikolaus.

Dienstag, 23.07.2019: Spectra and the Adams spectral sequence

Dr. Achim Krause (Universität Münster)

Homotopy groups of spaces are notoriously hard to compute. The situation becomes considerably more structured if we stabilize under suspension, leading to the world of stable homotopy theory. In this talk I want to give an introduction to stable homotopy theory, cohomology operations, and the Adams spectral sequence.

Donnerstag, 25.07.2019: Mathematik?! Und was macht man dann damit?

M. Schreiber (Berlin)

Untertitel: Aus dem Leben eines Freelancers

Donnerstag, 25.07.2019: Uniform boundary controllability of semi-discrete 1-d coupled wave equations

L. Maniar (Marrakesch)

Donnerstag, 25.07.2019: Some results for functionals of Aharanov-Bohm type

Prof. Michael Loss (Georgia Tech)

In this talk I present some variational problems of Aharanov-Bohm type, i.e., problems that include a magnetic flux that is entirely concentrated at a point. This is maybe the simplest example of a variational problems for systems;, the wave function being necessarily complex. The functional is rotationally invariant. The issue to be discussed is whether the optimizers have this symmetry or whether it is broken. This issue is addressed by exploiting a connection with the sharp version of the Caffarelli-Kohn-Nirenberg inequalities.

Freitag, 26.07.2019: Radeln oder Klettern? Ein Ausflug in die Computational Social Choice

B. Dorn (Tübingen)

Festvortrag im Rahmen des Goldenen Doktorjubiläums von Rainer Nagel und Ulf Schlotterbeck

Freitag, 26.07.2019: Punkte, Planeten, Prognostik: Himmlische Mathematik und fürstliche Macht

M. Korey (Dresden)

Festvortrag im Rahmen des Goldenen Doktorjubiläums von Rainer Nagel und Ulf Schlotterbeck