Upcoming talks Organizers
Archive:   Summer 2021   Spring 2021   Fall 2020   Summer 2020

This weekly seminar will cover topics related to point distributions, potential and discrepancy theory, and adjacent areas. The target audience is young researchers working in the listed directions, but everyone is welcome! Please share this information with anyone interested.

We meet on Wednesdays, at 10am CDT/11am EDT/5pm CEST. To join the seminar via Zoom, follow the link. It becomes active half an hour before the meeting. To join our mailing list, go here.

Previous talks are available in the Archive.

Coming up

  • June 16
    Assaf Goldberger (Tel Aviv U)
    Configurations, Automorphisms and Cohomology
    Point configurations on finite dimensional real or complex spaces, typically on the unit sphere, are important in Physics, Coding Theory, Classical and Quantum Information Theory, Geometry, Number Theory and more. The Automorphism group a of point configuration is a tool to study it, and to generate new ones. In this talk we will show how to generate automorphism groups from group-theoretic considerations, and how to construct configurations that satisfy the group. The main tool in use is Group Cohomology. We show that there is a spectral sequence which captures all possible solutions and all obstructions to the construction of a solution. In addition this sequence captures the Galois structure of algebraic configurations. Galois structures were discovered recently in the case of Zauner SIC-POVMs. This point of view can be generalized to a much broader framework, e.g. higher tensors as replacements of the Gramian matrix, perfect squares are seen to be dual to configuration Gramians when one uses homology instead of cohomology, and there are some connections to Number Theory, such as the theory of Brauer Groups. Other applications are the generation of Hadamard and Weighing matrices. We will discuss these extensions as time permits. This is joint work with Giora Dula.

    Slides: [pdf]
    Video: [mp4]

  • Schedule and speakers

    The schedule is given in the local time for CST (Chicago) / EST (New York) / CET (Paris, Berlin) time zones; during daylight saving time it remains 10am/11am/5pm, respectively.

    Date Time Speaker Affiliation Title
    Jun 2 *11:30am CDT/12:30pm EDT/6:30pm CEST Austin Anderson and Alex White Florida State Asymptotics of Best Packing and Best Covering
    Jun 9 10am CDT/11am EDT/5pm CEST Alan Legg Purdue Fort Wayne Logarithmic Equilibrium on the Sphere in the Presence of Multiple Point Charges
    Jun 16 10am CDT/11am EDT/5pm CEST Assaf Goldberger Tel Aviv U Configurations, Automorphisms and Cohomology
    Jun 30 10am CDT/11am EDT/5pm CEST Robert McCann UToronto TBA
    Jul 7 10am CDT/11am EDT/5pm CEST Alexander McDonald U of Rochester TBA
    Jul 14 10am CDT/11am EDT/5pm CEST Giuseppe Negro U of Birmingham TBA
    Jul 21 10am CDT/11am EDT/5pm CEST Jonathan Passant U of Rochester TBA
    Jul 28 10am CDT/11am EDT/5pm CEST Fátima Lizarte U of Cantabria TBA
    Aug 4 10am CDT/11am EDT/5pm CEST Jordi Marzo U of Barcelona TBA


    Ryan Matzke     U of Minnesota     matzk053@umn.edu
    Tetiana Stepaniuk     Universität zu Lübeck     stepaniuk@math.uni-luebeck.de
    Alex Vlasiuk     Florida State     ovlasiuk@fsu.edu

    Previously: Damir Ferizović     TU Graz     damir.ferizovic@math.tugraz.at