Aktuelle Vorträge und Veranstaltungen

Sommersemester 2020

Das Seminar findet bis auf weiteres über Zoom statt. Der Link wird am Morgen des Seminartermins via Zoom an die Mitglieder der Arbeitsgruppe geschickt. Falls Sie die Emails unserer Arbeitsgruppe nicht bekommen, melden Sie sich bitte mit einer kurzen Email an ulirsch[at]math.uni-frankfurt.de an.

The Seminar will be held via Zoom for the foreseeable future. The link will be sent to all members of our working group on the morning of the seminar. If you do not receive the emails of our working group, please register with a short email to ulirsch[at]math.uni-frankfurt.de.

Mi, 17. Juni 2020, Oberseminar Algebra und Geometrie (on Zoom)

  • 16:00-17:00: Frederik Benirschke (Stony Brook University): 

    The boundary of linear subvarieties

    Moduli spaces of meromorphic differential forms on Riemann surfaces, also known as strata, have a distinguished set of coordinates with linear transition functions, given by the periods of the differential; so called period coordinates. A special class of subvarieties of strata are linear subvarieties, which are algebraic subvarieties of the strata, given by linear equations in period coordinates. In particular, all GL(2,R)-orbit closures are linear subvarieties. We study the closure of linear subvarieties in the compactification of strata given by multi-scale differentials. The boundary of the space of multi-scale differentials has again a distinguished set of coordinates, similar to period coordinates, and we show that the boundary of linear subvarieties is given by linear equations in those coordinates.

Fr, 26. Juni 2020, TGiF-Seminar (on Zoom)

  • 14:00-15:00: Mark Gross (University of Cambridge):
  • 15:15-16:15: Luca Battistella (Ruprecht-Karls-Universität Heidelberg)
  • 16:30-17:30: Kalina Mincheva (Yale University)

Di, 7. Juli 2020, Oberseminar Algebra und Geometrie (on Zoom)

  • 14:30-15:30: Jeonghoon So (Goethe-Universität Frankfurt): 

    Derivierte \infty-Kategorien (Master-Abschlussvortrag)

Mi, 8. Juli 2020, Oberseminar Algebra und Geometrie (on Zoom)

  • 15:00-16:00: Annette Werner (Goethe-Universität Frankfurt):

Mi, 15. Juli 2020, Oberseminar Algebra und Geometrie (on Zoom)

  • 14:30-15:30: Ming-Hao Quek (Brown University):


- Bereits gehaltene Vorträge im SoSe 2020 -

Fr, 24. April 2020 TGiF-Tropical Geometry in Frankfurt - First meeting in Summer Semester 2020

  • 14:00-15:00
    Marta Panizzut (TU Berlin)

    15:00-15:30 - Coffee Break -

  • 15:30-16:30
    Alejandro Vargas (Universität Bern)

  • 16:45-17:45
    Prof. Dr. Jan Draisma (Universität Bern)

Mi, 13. Mai 2020, Oberseminar Algebra und Geometrie (on Zoom)

  • 17:30-18:30: Hannah Larson (Stanford University):
    Vector bundles on P^1 bundles

    Abstract: Every vector bundle on P^1 splits as a direct sum of line bundles. Given a vector bundle E on a P^1 bundle PW --> B, the base B is stratified by subvarieties defined by the condition that the restriction of E to the fibers has a certain splitting type. It is natural to ask for the classes of the closures of these strata in the Chow ring of B. In joint work with Ravi Vakil, we answer this question through a study of the moduli stack of vector bundles on P^1 bundles. In describing this moduli space, we discover an algebraic version of Bott periodicity. I will also discuss applications of this work to the Brill-Noether theory of curves of low gonality.

Mi, 20. Mai 2020, Oberseminar Algebra und Geometrie (on Zoom)

  • 16:00-17:00: Emanuel Reinecke (University of Michigan):
    The cohomology of the moduli space of curves at infinite level
  • Abstract: By work of Harer, the Betti cohomology of the moduli space of smooth, complex curves of genus g > 1 vanishes in degrees above 4g - 5. In my talk, I give a new perspective on this result which is inspired by recent developments in p-adic geometry. The approach also yields statements about moduli of stable curves and curves of compact type that are not covered by Harer's methods.

Fr, 26. Mai 2020 TGiF-Tropical Geometry in Frankfurt - Second meeting in Summer Semester 2020

  • 14:00-15:00
    Ben Smith (University of Manchester):
    Faces of tropical polyhedra
  • 15:15-16:15
    Yue Ren (Swansea University):
    Tropical varieties of neural networks
  • 16:30-17:30
    Hannah Markwig (Eberhard-Karls-Universität Tübingen):
    The combinatorics and real lifting of tropical bitangents to plane quartics