Current
The seminar is held on Tuesdays from 11 to 12 and is organised by Razvan Barbulescu and Wessel van Woerden. Unless otherwise stated it takes place in room 2 of IMB. To get announcements, you can subscribe to the mailing list of the Bordeaux number theory seminars. Last minute changes may appear first on the IMB website.
- 2024-04-3011:00Salle 2Lars Ran (Radboud University)Analysing multi-graded polynomial systems; a step towards more precise security estimationsGenerally, polynomial systems that arise in algebraic cryptanalysis have extra structure compared to generic systems, which comes from the algebraic modelling of the cryptographic scheme. Sometimes, part of this extra structure can be caught with polynomial rings with non-standard grading. For example, in the Kipnis-Shamir modelling of MinRank one considers the system over a bi-graded polynomial ring instead. This allows for better approximations of the solving degree of such systems when using Gröbner basis algorithms. In this talk, I will present ongoing work in which this idea is extended to multi-graded polynomial rings. Furthermore, I will show how we can use this grading to tailor existing algorithms to use this structure and speed up computation.
- 2024-05-0711:00Salle 2Felix Huber (LaBRI)TBA
- 2024-05-1411:00Salle 2Oana Padurariu (Max-Planck-Institut für Mathematik, Bonn)Bielliptic Shimura curves X_0^D(N) with nontrivial levelIn this talk, I explain how we work towards completely classifying all bielliptic Shimura curves X_0^D(N) with nontrivial level N, extending a result of Rotger that provided such a classification for level 1. This allows us to determine the list of all pairs (D,N) for which X_0^D(N) has infinitely many degree 2 points, up to three explicit possible exceptions. This is joint work with Frederick Saia.
- 2024-05-2811:00Salle 2Jérémie Berthomieux (Sorbonne Université)TBA
- 2024-06-1111:00Salle 2Maria Corte-Real Santos (University College London)TBA
- 2024-06-1111:00Salle 2Valentijn Karemaker (Universiteit Utrecht)TBA