Around additive combinatorics

This mini-symposium will take place during the 2026 European Women in Mathematics General Meeting, at the Mathematics Institute of the University of Warwick (Coventry, UK), on thursday afternoon (03/08/2026). Room/building will be written here. For more information on the general event, see the link: https://sites.google.com/europeanwomeninmaths.org/ewm2026warwick/home

• 13:30-13:50. Katherine Thomas  (University of Oxford): Sums of Niven numbers via the circle method

Abstract: A base-g Niven number is an integer divisible by the sum of its digits in base g. We show that all sufficiently large integers are the sum of three base-g Niven numbers. The proof uses the circle method, which we also use to count the number of ways to write an integer as the sum of three integers with certain fixed digit sums. 

• 14:00-14:20. Mengdi Wang (EPFL): Green-Tao theorem in sparse primes

Abstract: In this talk, I will introduce a new quantitative dense model that improves the bounds of Gowers (2010) and Reingold et al. (2008). I will then discuss potential applications of this dense model to arithmetic questions, such as refining quantitative bounds in the Green--Tao theorem for primes. This is based on joint work with Joni Teräväinen.

• 14:30-14:50. Candida Bowtell (University of Birmingham): Rainbow structures in edge-coloured graphs

Abstract: A properly edge-coloured graph is a graph in which the edges are coloured so that no vertex is incident to two edges of the same colour. A subgraph H is rainbow if every colour appears on at most one edge in H. In this talk we will discuss some recent results concerning large rainbow structures in properly edge-coloured complete graphs, and some links to additive combinatorics.  

• Break !

• 15:30-15:50. Mieke Etine Wessel (Inria Saclay): How to do additive combinatorics in function fields

Abstract: Sumsets form a core object in the study of additive combinatorics. In recent years a link has been made between sumsets and something called the Schur product of linear spaces, which has many applications in both coding theory and cryptography. In fact it turns out that we can state many classical theorems from additive combinatorics in a more general setting, involving function fields. In this setup our sets are replaced by linear spaces and addition makes way for multiplication. We will explain what this link looks like, give some examples of obstructions that appear in the function field case and give a short overview of some applications. 

• 16:00-16:20. Emma Weschler (University of Lille): Generalizing Strong Uncertainty Principle to finite abelian groups

Abstract: I will present in this talk the evolution of the study of Strong Uncertainty Principle over finite abelian groups, that is an inequality linking additively the size of the support of a function and its Fourier Transform. Initiated by Tao in 2005 on finite fields of prime order, this notion has been generalized by Garcia, Karaali and Katz in 2021 for functions defined on a general finite field, satistfying a certain symmetry condition with respect to a subgroup of the non zero elements. Recently, I have generalized this framework to a general finite abelian group, and I will present some results on the group of the intergers modulo n, for a non prime n. 

This mini-symposium is organized by Emma Weschler, contact: firstname[dot]lastname[at]univ-lille[dot]fr