Sommersemester 2026

08.04.2026 um 17:15 Uhr in Raum 69/12

Prof. Dr. Martin Frankland, Ph.D (University of Regina, Canada)

Quillen Cohomology of Divided Power Algebras over an Operad

In topology, cohomology is an invariant we can assign to spaces. In algebra, there are also cohomology theories for various algebraic structures, such as group cohomology, Lie algebra cohomology, and André-Quillen cohomology of commutative rings. Quillen cohomology provides a cohomology theory for any algebraic structure. It has been studied notably for divided power algebras and restricted Lie algebras, both of which are instances of divided power algebras over an operad: the commutative and Lie operad respectively. I will describe joint work with Ioannis Dokas and Sacha Ikonicoff generalizing this to other operads. My main goal will be to introduce the three ingredients in the title.

22.04.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Frank Aurzada (Technische Universität Darmstadt)

Brownian Motion - Conditioned on Atypical Events

06.05.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Damaris Schindler (Georg-August-Universität Göttingen)

TBA

13.05.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Relinde Jurrius ( Netherlands Defence Academy) 

q-Analogues in Combinatorics 

03.06.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Franz Schuster (TU Wien)

Radon Transforms of Projection Functions and Aleksandrov–Fenchel Inequalities

The Radon transforms on Grassmannians define a family of geometric maps on convex bodies when applied to their projection functions. These operators coincide on origin-symmetric bodies with the mean section operators introduced in the 1990s by Goodey and Weil and are dual, via the Alesker-Fourier transform, to Minkowski’s family of projection body maps. Over the past two decades various results, including sharp isoperimetric type inequalities, established for projection body maps towards the end of the previous century were shown to also hold for the mean section operators. However, a dual to Lutwak’s family of Brunn-Minkowski type inequalities for the intrinsic volumes of the projection body maps remained open for mean section operators in full generality with several partial results being proved since the early 2000s. In this talk, we present new Alesksandrov–Fenchel inequalities for certain averages of mixed volumes that are the key to show that also all the intrinsic volumes of the Radon transforms of projection functions are indeed log-concave.
(joint work with L. Brauner and O. Ortega-Moreno)
 

17.06.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Joe Kileel (University of Texas at Austin)

TBA

24.06.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Johanna Schönherr (Universität Osnabrück)

TBA / Antrittsvorlesung

08.07.2026 um 17:15 Uhr in Raum 69/125

Prof. Dr. Sabrina Streipert (University of Pittsburgh)

TBA