10h30: Deformation techniques for triangular arithmetic. Éric Schost, University of Western Ontario, Canada.

Triangular representations are a versatile data structure; however, even basic arithmetic operations raise difficult questions with such objects. I will present an algorithm for multiplication modulo a triangular set that relies on deformation techniques and ultimately evaluation and interpolation. It features a quasi-linear running time (without hidden exponential factor), at least in some nice cases. Applications include polynomial multiplication, operations on algebraic numbers and arithmetic in Artin-Schreier extensions.