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.

• 2024-11-19
  11:00
  Salle 2
  Fabien Pazuki (University of Copenhagen)
  Cycloalkanes and elliptic curves
  The aim of the talk is to explain an unexpected link between a class of molecules composed of carbon and hydrogen atoms, and the theory of elliptic curves over finite fields. The correspondence is of topological nature and doesn't include, so far, any of the crucial geometric features of the cycloalkanes. We will nevertheless explain how modular curves help making this connection, the role of modular polynomials, give details about explicit computations we performed, and give several examples. The talk is based on joint work with Henry Bambury and Francesco Campagna.
• 2024-11-26
  11:00
  Salle 2
  Guilhem Mureau (CANARI)
  Cryptanalysis of rank 2 Module-LIP for certain number fields
  In 2022, Ducas et al. introduced the signature scheme Hawk, based on the presumed hardness of a new problem in lattice-based cryptography: the Lattice Isomorphism Problem for the module-lattice $O_L^2$, where $L$ is a cyclotomic number field. Last year we presented a polynomial time algorithm solving this problem when $L$ is a totally real number field (thus not affecting the security of Hawk). More recently, we provided a reduction of the same problem when $L$ is now a CM field (thus containing Hawk's instance) to the problem of finding a generator of a principal quaternionic ideal. In this talk we give a framework containing both the totally real and the CM case, and we will discuss the differences. This is based on a joint work with C. Chevignard, P-A. Fouque, A. Pellet-Mary, H. Pliatsok and A. Wallet.
• 2024-12-03
  11:00
  Salle 2
  Florian Breuer (University of Newcastle, Australia)
  TBA
• 2024-12-17
  11:00
  Salle 2
  Rob de Jeu (Vrije Universiteit Amsterdam)
  TBA