Aktuelle Vorträge und Veranstaltungen


Sommersemester 2017


Do, 29. Juni 2017  Oberseminar

  • Piotr Achinger (IHES):
    Wild ramification and K(π, 1) spaces
    Zeit und Ort: 15:00 im Raum 711 (groß), Robert-Mayer-Str. 10.

    I will sketch the proof that every connected affine scheme in positive characteristic is a K(π, 1) space for the etale topology. The key technical ingredient is a “Bertini-type” statement regarding the wild ramification of ℓ-adic local systems on affine spaces. Its proof uses in an essential way recent advances in higher ramification theory due to T. Saito. Time permitting, I will discuss some "anabelian" and "irregular" ramifications of the result.

Do, 13. Juli 2017  Darmstadt-Frankfurt-Seminar (Programm)

  • Ana Maria Botero (Darmstadt):
    Toroidal Embeddings and compacti cations of Hilbert modular surfaces.
    Zeit und Ort: 15:00 im Raum 711 (groß), Robert-Mayer-Str. 10.
  • Jakob Stix (Frankfurt):
    Model of Hilbert modular variety. 
    Zeit und Ort: 16:30 im Raum 711 (groß), Robert-Mayer-Str. 10.

gehaltene Vorträge:

Mi, 19. April 2017 Abschlussseminar

  • Noleen Köhler: Korrespondenzsätze zwischen topologischen und
    tropischen Überlagerungen und ihre Spinstruktur

    Zeit und Ort: 14:00 im Raum 110, Robert-Mayer-Str. 10.

Do, 11. Mai 2017  Darmstadt-Frankfurt-Seminar (Programm)

  • Rosemarie Martienssen (Frankfurt):
    Toric Varieties 1
    Zeit und Ort: 15:00 im Raum 711 (groß), Robert-Mayer-Str. 10.
  • Max Bieri (Frankfurt):
    Toric Varieties 2
    Zeit und Ort: 16:30 im Raum 711 (groß), Robert-Mayer-Str. 10.

Mi,  07. Juni 2017  

  • Rico Krause:
    Bachelor-Vortrag „Darstellung orientierter Flächen als Nullstellengebilde von Polynomen im R3"
    Zeit und Ort: 14:15 im Raum 309, Robert-Mayer-Str. 6-8.

Do, 08. Juni 2017  Darmstadt-Frankfurt-Seminar (Programm)

  • Martin Möller (Frankfurt):
    Toric modular forms 2.
    Zeit und Ort: 15:00 im Raum 711 (groß), Robert-Mayer-Str. 10.
  • Moritz Dittmann (Darmstadt):
    Toric modular forms 3.
    Zeit und Ort: 16:30 im Raum 711 (groß), Robert-Mayer-Str. 10.

Mi, 14. Juni 2017 Abschlussseminar

  • Melda Görür: Torische Codes und endliche Geometrien
    Zeit und Ort: 14:00 im Raum 308, Robert-Mayer-Str. 6-8.

Mi, 21. Juni 2017  Oberseminar

  • Martin Ulirsch (University of Michigan):
    A moduli stack of tropical curves
    Zeit und Ort: 14:15 im Raum 308, Robert-Mayer Str. 6-8.

    The moduli space of tropical curves (and its variants) are some of the most-studied objects in tropical geometry. So far this moduli space has only been considered as an essentially set-theoretic coarse moduli space (sometimes with additional structure). As a consequence of this restriction, the tropical forgetful map does not functions as a universal curve (at least in the positive genus case). The classical work of Deligne-Knudsen-Mumford has resolved a similar issue for the algebraic moduli space of curves by considering the fine moduli stacks instead of the coarse moduli spaces.

    In this talk I am going to give an introduction to these fascinating moduli spaces and discuss recent work  with Renzo Cavalieri, Melody Chan, and Jonathan Wise (arXiv 1704.03806), where we propose the notion of a moduli stack of tropical curves as a geometric stack over the category of rational polyhedral cones. Using this 2-categorical framework one can give a natural interpretation of the forgetful morphism as a universal curve. Moreover, I will propose a way of describing the process of tropicalization via logarithmic geometry in the sense of Kato-Illusie using the theory of Artin fans. Finally, given time, I will also report on an ongoing  follow-up project (joint with Margarida Melo, Filippo Viviani, and Jonathan Wise) that uses these techniques to construct a universal Picard variety in logarithmic and tropical geometry.