{ "id": "1812.08969", "version": "v1", "published": "2018-12-21T06:37:14.000Z", "updated": "2018-12-21T06:37:14.000Z", "title": "Particle dynamics subject to impenetrable boundaries: existence and uniqueness of mild solutions", "authors": [ "M. Kimura", "P. van Meurs", "Z. X. Yang" ], "categories": [ "math.AP" ], "abstract": "We consider the dynamics of particle systems where the particles are confined by impenetrable barriers to a bounded, possibly non-convex domain $\\Omega$. When particles hit the boundary, we consider an instant change in velocity, which turns the systems describing the particle dynamics into an ODE with discontinuous right-hand side. Other than the typical approach to analyse such a system by using weak solutions to ODEs with multi-valued right-hand sides (i.e., applying the theory introduced by Filippov in 1988), we establish the existence of mild solutions instead. This solution concept is easier to work with than weak solutions; e.g., proving uniqueness of mild solutions is straight-forward, and mild solutions provide a solid structure for proving many-particle limits. We supplement our theory of mild solutions with an application to gradient flows of interacting particle energies with a singular interaction potential, and illustrate its features by means of numerical simulations on various choices for the (non-convex) domain $\\Omega$.", "revisions": [ { "version": "v1", "updated": "2018-12-21T06:37:14.000Z" } ], "analyses": { "keywords": [ "mild solutions", "particle dynamics subject", "impenetrable boundaries", "uniqueness", "weak solutions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }