Álvaro del Pino Gomez (Utrecht University)

Thurston’s jiggling

In the mid 1970s, Thurston settled the existence problem for foliations of codimension 1 (showing that any manifold of vanishing Euler characteristic has such a foliation) and the classification problem for higher-codimension foliations. In this talk I will explain one of the ingredients of the proof, called jiggling.

If time allows, I will comment on some on-going work joint with A. Fokma and L. Toussaint generalising jiggling. Our main observation is that jiggling is the first example of an “h-principle without homotopical assumptions” and can indeed be related to other h-principle techniques, like convex integration.

Francesca Arici (Leiden University)

Title and abstract to be announced

Oliver Lorscheid (University of Groningen)

Moduli spaces in matroid theory

Families of matroids have appeared in different disguises during the last few decades: combinatorial flag varieties arise from flag matroids, Macphersonians appear as spaces of oriented matroids, Dressians consist of valuated matroids. With the advent of F1-geometry, we are able to understand these spaces from an algebro-geometric perspective as rational point sets of moduli spaces of (flag) matroids and place them into a larger landscape of geometric objects stemming from combinatorics. In this talk, I will give an impression of my joint works with Matthew Baker and with Manoel Jarra on the topic.