Discrepancy of a barrel

Date/heure
12 mars 2026
15:45 - 16:45

Lieu
Salle de séminaires Metz

Oratrice ou orateur
Roberto Bramati (Università di Bergamo)

Catégorie d'évènement
Séminaire Théorie de Lie, Géométrie et Analyse


Résumé

The discrepancy of a distribution of $N$ points in the torus $T^d$ with respect to a given family of test sets measures how far the points are from being uniformly distributed over that family. When the family consists of all translates of a fixed set, one can consider the $L^2$-average of the discrepancy over translations and use Fourier analytical methods to understand its size. Sharp lower bounds for such $L^2$ discrepancy in terms of $N$ are known for wide classes of sets in $T^2$, but much less is known in higher dimensions. In this talk, I will report on recent progress in this direction, focusing on a family of test
sets with “cylindrical” symmetry that can be defined in any dimension. In three dimensions, these sets have the shape of a barrel. They are particularly
interesting because they exhibit geometric features known to play a key role in discrepancy theory: flat regions, curved regions, and corners. Joint work with
Luca Brandolini and Alessandro Monguzzi.