{ "id": "2104.02795", "version": "v1", "published": "2021-04-06T21:26:23.000Z", "updated": "2021-04-06T21:26:23.000Z", "title": "Besov regularity for a class of singular or degenerate elliptic equations", "authors": [ "Pasquale Ambrosio" ], "categories": [ "math.AP", "math.CA" ], "abstract": "Motivated by applications to congested traffic problems, we establish higher integrability results for the gradient of local weak solutions to the strongly degenerate elliptic PDE $-\\mathrm{div}\\left((\\vert\\nabla u\\vert-1)_{+}^{q-1}\\frac{\\nabla u}{\\vert\\nabla u\\vert}\\right)=f,\\,\\,\\mathrm{in}\\,\\,\\Omega$, where $\\Omega$ is a bounded domain in $\\mathbb{R}^{n}$ for $n\\geq2$, $1