Birational and Tropical Methods in Geometry

ended

We propose major advances in several fundamental questions of algebraic geometry, centering around the invariants of varieties, that we will attack on two fronts. One direction considers birational invariants and rationality properties. The other studies deformation properties of varieties, especially in terms of curve-counting invariants. Accordingly, we divide the material into three main projects. In the first, we will prove rationality theorems for many new birational quotients obtained via divided powers. The second project sets up a novel method of counting tropical curves, that will lead to results on tropical correspondences. Our third project extends the ideas of the second, proving deep enumerative results in log geometry; we expect this to provide a state-of-the-art enumerative interpretation of the divisor-line bundle equivalence in log tropical terms. The University of Warwick is the ideal venue for this research. The PI will benefit from the extensive experience of Miles Reid and Christian Böhning, world experts in birational geometry and the modern study of rationality questions, and from collaboration with Diane Maclagan, an acknowledged authority in tropical geometry.