September 10, 2023
TITLE: Stratified hyper-Kähler moduli spaces and physics
ABSTRACT: Singular hyper-Kähler varieties are stratified into smooth subsets called symplectic leaves. In recent years the 3d Coulomb branch construction of hyper-Kähler varieties has been a powerful tool to study this stratification, going under the name of quiver subtraction. This algorithm is derived from intuition coming from physics, and in particular brane systems. We will review the concept of this stratification, as well as some computational methods and physical interpretations.