{ "id": "math/0609591", "version": "v1", "published": "2006-09-21T05:55:03.000Z", "updated": "2006-09-21T05:55:03.000Z", "title": "Asymptotic stability of harmonic maps under the Schrödinger flow", "authors": [ "Stephen Gustafson", "Kyungkeun Kang", "Tai-Peng Tsai" ], "comment": "41 pages", "categories": [ "math.AP", "math-ph", "math.MP" ], "abstract": "For Schr\\\"odinger maps from $\\R^2\\times\\R^+$ to the 2-sphere $\\S^2$, it is not known if finite energy solutions can form singularities (``blowup'') in finite time. We consider equivariant solutions with energy near the energy of the two-parameter family of equivariant harmonic maps. We prove that if the topological degree of the map is at least four, blowup does {\\it not} occur, and global solutions converge (in a dispersive sense -- i.e. scatter) to a fixed harmonic map as time tends to infinity. The proof uses, among other things, a time-dependent splitting of the solution, the ``generalized Hasimoto transform\", and Strichartz (dispersive) estimates for a certain two space-dimensional linear Schr\\\"odinger equation whose potential has critical power spatial singularity and decay. Along the way, we establish an energy-space local well-posedness result for which the existence time is determined by the length-scale of a nearby harmonic map.", "revisions": [ { "version": "v1", "updated": "2006-09-21T05:55:03.000Z" } ], "analyses": { "subjects": [ "35Q55", "35B40" ], "keywords": [ "asymptotic stability", "schrödinger flow", "energy-space local well-posedness result", "critical power spatial singularity", "nearby harmonic map" ], "note": { "typesetting": "TeX", "pages": 41, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......9591G" } } }