{ "id": "1708.04759", "version": "v1", "published": "2017-08-16T03:35:58.000Z", "updated": "2017-08-16T03:35:58.000Z", "title": "A Nonlinear Plancherel Theorem with Applications to Global Well-Posedness for the Defocusing Davewy-Stewartson Equation and to the Inverse Boundary Value Problem of Calderon", "authors": [ "Adrian I. Nachman", "Idan Regev", "Daniel I. Tataru" ], "comment": "38 pages", "categories": [ "math.AP" ], "abstract": "We prove a Plancherel theorem for a nonlinear Fourier transform in two dimensions arising in the Inverse-Scattering method for the defocusing Davey-Stewartson II equation. We then use it to prove global well-posedness and scattering in $L^2$ for defocusing DSII. This Plancherel theorem also implies global uniqueness in the inverse boundary value problem of Calder\\'on in dimension $2$, for conductivities $\\sigma>0$ with $\\log \\sigma \\in \\dot H^1$. The proof of the nonlinear Plancherel theorem includes new estimates on fractional integrals in Sobolev spaces, as well as a new result on $L^2$- boundedness of pseudo-differential equations with non-smooth symbols, valid in all dimensions.", "revisions": [ { "version": "v1", "updated": "2017-08-16T03:35:58.000Z" } ], "analyses": { "keywords": [ "inverse boundary value problem", "nonlinear plancherel theorem", "defocusing davewy-stewartson equation", "global well-posedness" ], "note": { "typesetting": "TeX", "pages": 38, "language": "en", "license": "arXiv", "status": "editable" } } }