10.07.2025, 16:15
– Raum 1.22
Forschungsseminar Differentialgeometrie
Cancellation properties of exotic 4-dimensional positive scalar curvature metrics
Johannes Ebert (Münster)
Matthias Ludewig (Adelaide)
Recently, physicists have been able to create “topological states” localised on the boundary of a 2D system, which have rather crazy properties: they fill up spectral gaps in the boundary-less 2D problem, and have quantised propagation along the boundary regardless of its shape. I will exhibit how operator K-theory can be used to explain this phenomenon.