{ "id": "2301.07086", "version": "v1", "published": "2023-01-17T18:52:06.000Z", "updated": "2023-01-17T18:52:06.000Z", "title": "A continuum limit for the Laplace operator on metric graphs", "authors": [ "Sidney Holden", "Geoffrey Vasil" ], "categories": [ "math-ph", "math.MP" ], "abstract": "Metric graphs -- with continuous real-valued edges -- have been studied extensively as domains for solutions of PDEs. We study the action of the Laplace operator on each edge as a metric graph fills in a $n-$dimensional Riemannian manifold, e.g., a very dense spider web in the planar disc or ball of wire within the $2-$sphere. We derive an $n$-dimensional limiting differential operator whose low-order eigenmodes approximate the low-order eigenmodes of the metric graph Laplace operator. High-density metric graphs exhibit nontrivial, continuum-like behaviour at low frequencies and purely graph-like behaviour at high frequencies. In the continuum limit, we find the emergence of a new symmetric tensor field but with an unusual distance scaling compared to the traditional Riemannian metric. The limiting operator from a metric graph implies a possible new kind of continuous geometry.", "revisions": [ { "version": "v1", "updated": "2023-01-17T18:52:06.000Z" } ], "analyses": { "keywords": [ "continuum limit", "metric graph laplace operator", "traditional riemannian metric", "dimensional riemannian manifold", "dense spider web" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }