Special Session 126: Defects, Microstructures, and Failure: Multiscale Variational Models

The random fractional obstacle problem
Caterina Ida Zeppieri
University of Muenster
Germany
Co-Author(s):    Francesco Deangelis, Matteo Focardi
Abstract:
Nonlocal energies, such as fractional Sobolev seminorms, arise naturally in mathematical models involving long-range interactions. In this talk, we study minimizers of such energies that vanish on a collection of small balls with random centers and radii, leading to a bilateral (fractional) obstacle problem. We will present a homogenization result that holds under minimal assumptions on the distribution and size of the obstacles, which are generated by a stationary marked point process. In particular, the obstacles may overlap and form clusters with positive probability, giving rise to a complex microstructure. Our analysis identifies the limiting energy and shows how it reflects the underlying probability distribution of the obstacles.