Institute of
Discrete Mathematics and Geometry

Discrete Mathematics Working Group (Arbeitsgemeinschaft Diskrete Mathematik, AGDM)

Info: The AGDM seminar is a joint seminar of the University of Vienna and TU Wien. In winter semesters, we meet on Tuesdays from 15:00 to 16:30 at the University of Vienna. In summer semesters, we meet on Tuesdays from 15:15 to 16:45 at TU Wien.

Since 2025, we use a mailing-list to advertise the seminar. You can register here.

Place: University of Vienna, Oskar-Morgenstern-Platz 1, BZ 09 (first room on the right on the 9th floor)

Time:Tuesday, 15:00-16:30

Next talk

Date: Tuesday 04.11.2025
Title: Some New Examples of Modular Congruence Multiplicities
Speaker: Nicolas Allen Smoot (University of Vienna)
Abstract: The Fourier coefficients of modular forms often count interesting arithmetic and combinatorial objects. For example, the inverted Dedekind eta function counts integer partitions. Such coefficients also tend to feature noteworthy divisibility properties and $p$-adic behavior. These properties can vary enormously in their difficulty: some are quite easy to prove, while others remain standing conjectures. A recent development is the discovery that the divisibility properties for the coefficients of one modular form can often manifest in the coefficients of another quite different form. This provides us with a useful tool for proving conjectured congruence families. We will show a few examples of this phenomenon, which we call "congruence multiplicity."

Code of conduct

Maintaining a respectful environment is essential to fostering meaningful dialogue and intellectual growth. Participants are expected to refrain from any form of disrespectful or inappropriate behaviour, including offensive comments, harassment, or disruptive conduct. Questions and contributions should be constructive, relevant to the topic, and posed in a professional manner that encourages healthy academic exchange. Harassment of any kind—including verbal, moral or physical—will not be tolerated, and all attendees are urged to uphold these principles to ensure a safe and welcoming atmosphere for everyone.

Upcoming talks

18.11.2025Fabián Levicán
25.11.2025Joshua Jeishing Wen
02.12.2025Marcus Schönfelder
09.12.2025
16.12.2025Atsuro Yoshida
13.01.2026
20.01.2026Markus Reibnegger
27.01.2026Mona Gatzweiler

Talks in the past years

Talks of years 2005 - 2025

Past talks of this year

04.11.2025Eva-Maria Hainzl (TU Wien)Functional equations with catalytic variable 101
28.10.2025Shane Chern (University of Vienna)The Koutschan-Krattenthaler-Schlosser determinants and their combinatorics
21.10.2025Sergio Alejandro Fernandez de Soto Guerrero (TU Graz)MathMagic: A positroidal action over a deck of cards
14.10.2025Christian Krattenthaler (University of Vienna)Two Topics, Four Lessons
07.10.2025Matija Bucic (University of Vienna)Equiangular lines via improved eigenvalue multiplicity