The resolution of singular foliations on analytic manifolds and algebraic varieties is a notoriously challenging problem, with only a few known partial results. In characteristic zero, we construct principalization of ideals on smooth foliated varieties. As an application, we prove the desingularization of Darboux totally integrable foliations in arbitrary dimensions, including both rational and meromorphic Darboux foliations. Additionally, we show how to transform a generically transverse section into a fully transverse one. Our approach relies on torus actions and uses weighted cobordant blow-ups, and is closely related to the analogous method of resolution of singularities of varieties.This is joint work with Abramovich, Belotto, and Temkin.[-]

One of the possible applications of Artin approximation is to prove that the local geometry of sets defined in affine space by real or complex analytic equations is not more complicated than the local geometry of sets defined by polynomial equations. A possible approach is to prove that a complex analytic (singular) germ, for example $(X,0) \subset (\mathbf{C} ^n,0)$, is the intersection, in some affine space $\mathbf{C}^N$, of an algebraic germ $(Z,0) \subset (\mathbf{C}^N,0)$ by a complex analytic non singular subspace $(W,0)$ of dimension $n$ which is "in general position" with respect to $Z$ at the origin. Approximating $Z$ by an algebraic subspace then yields the desired result, provided the "general position" condition is sufficiently precise. I will explain how one can attack this problem using a notion of "general position with respect to a singular space" which is based on the concept of minimal Whitney stratification, which will also be explained. Nested Artin approximation is essential in this approach.

nested Artin approximation - Whitney forms - singularities - stratifications - germ of subspace[-]

The space of formal arcs of an algebraic variety carries part of the information encoded in a resolution of singularities. This series of lectures addresses this fact from two perspectives. In the first two lectures, we focus on the topology of the space of arcs, proving Kolchin's irreducibility theorem and discussing the Nash problem on families of arcs through the singularities of the variety; recent results on this problem are proved in the second lecture. The last two lectures are devoted to some applications of arc spaces toward a conjecture on minimal log discrepancies known as inversion of adjunction. Minimal log discrepancies are invariants of singularities appearing in the minimal model program, a quick overview of which is given in the third lecture.[-]

The series aims to introduce resolution of singularities for non-experts, with foliation specialists in mind. The work discussed is joint with Andé Belotto da Silva, Michael Temkin and Jaroslaw Wlodarczyk.

Talk 1: Resolution of singularities in characteristic 0 - why does it work?

I continue a long struggle to explain to non-experts why resolution of singularities in characteristic zero works. I explain a criterion, one paragraph in an article by Wlodarczyk, which tells you what you need in order to resolve singularities.[-]