Cohomological Invariants of Configurations of Lines

by Daniel Matei (IMAR Bucharest)

Friday 5 Dec 2025, 10:00 → 11:00 Europe/Brussels

B/2nd floor-B.203 - Seminar room (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

We will discuss the relationship between the combinatorics, geometry, and topology of configurations of lines in the projective plane. We introduce geometric invariants of plane curves inspired by the classical theorems of Menelaus and Carnot. In the case of line configurations, we relate these invariants to the cohomology of the complement of the union of the lines. We exhibit various classes of configurations of lines, related to finite geometries, that have special cohomological properties.