{ "id": "1807.07551", "version": "v1", "published": "2018-07-19T17:43:24.000Z", "updated": "2018-07-19T17:43:24.000Z", "title": "Stability of vacuum for the Landau equation with moderately soft potentials", "authors": [ "Jonathan Luk" ], "categories": [ "math.AP" ], "abstract": "Consider the spatially inhomogeneous Landau equation with moderately soft potentials (i.e. with $\\gamma \\in (-2,0)$) on the whole space $\\mathbb R^3$. We prove that if the initial data $f_{\\mathrm{in}}$ are close to the vacuum solution $f_{\\mathrm{vac}} \\equiv 0$ in an appropriate norm, then the solution $f$ remains regular globally in time. This is the first stability of vacuum result for a binary collisional model featuring a long-range interaction. Moreover, we prove that the solutions in the near-vacuum regime approach solutions to the linear transport equation as $t\\to +\\infty$. Furthermore, in general, solutions do not approach a traveling global Maxwellian as $t \\to +\\infty$. Our proof relies on robust decay estimates captured using weighted energy estimates and the maximum principle for weighted quantities. Importantly, we also make use of a null structure in the nonlinearity of the Landau equation which suppresses the most slowly-decaying interactions.", "revisions": [ { "version": "v1", "updated": "2018-07-19T17:43:24.000Z" } ], "analyses": { "keywords": [ "moderately soft potentials", "near-vacuum regime approach solutions", "linear transport equation", "robust decay estimates", "vacuum result" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }