# Mathematics Colloquia and Seminars

### $4m-3$ Lattice Points in the Plane
Tverberg's theorem says that sufficiently many points in euclidean space can always be partitioned into $m$ subsets so that the intersection of the convex hulls of the $m$ subsets is non-empty. In the 1970's Doignon proposed a variant of Tverberg's theorem where the points are required to have integer coordinates. We will focus on this variant throughout the talk, and sketch the proof that any $4m−3$ (for $m≥3$) lattice points in the plane can be colored $m$ colors so that there is a lattice point in the intersection of the convex hulls of the $m$ colors. We will also discuss the analogous problem in higher dimensions.