{ "id": "1509.08845", "version": "v1", "published": "2015-09-29T16:53:53.000Z", "updated": "2015-09-29T16:53:53.000Z", "title": "Blowup for fractional NLS", "authors": [ "Thomas Boulenger", "Dominik Himmelsbach", "Enno Lenzmann" ], "comment": "25 pages. Comments are welcome", "categories": [ "math.AP", "math-ph", "math.MP" ], "abstract": "We consider fractional NLS with focusing power-type nonlinearity $$i \\partial_t u = (-\\Delta)^s u - |u|^{2 \\sigma} u, \\quad (t,x) \\in \\mathbb{R} \\times \\mathbb{R}^N,$$ where $1/2< s < 1$ and $0 < \\sigma < \\infty$ for $s \\geq N/2$ and $0 < \\sigma \\leq 2s/(N-2s)$ for $s < N/2$. We prove a general criterion for blowup of radial solutions in $\\mathbb{R}^N$ with $N \\geq 2$ for $L^2$-supercritical and $L^2$-critical powers $\\sigma \\geq 2s/N$. In addition, we study the case of fractional NLS posed on a bounded star-shaped domain $\\Omega \\subset \\mathbb{R}^N$ in any dimension $N \\geq 1$ and subject to exterior Dirichlet conditions. In this setting, we prove a general blowup result without imposing any symmetry assumption on $u(t,x)$. For the blowup proof in $\\mathbb{R}^N$, we derive a localized virial estimate for fractional NLS in $\\mathbb{R}^N$, which uses Balakrishnan's formula for the fractional Laplacian $(-\\Delta)^s$ from semigroup theory. In the setting of bounded domains, we use a Pohozaev-type estimate for the fractional Laplacian to prove blowup.", "revisions": [ { "version": "v1", "updated": "2015-09-29T16:53:53.000Z" } ], "analyses": { "keywords": [ "fractional nls", "fractional laplacian", "general blowup result", "exterior dirichlet conditions", "pohozaev-type estimate" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }