BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Lauri Oksanen (University College London) DTSTART:20200903T160000Z DTEND:20200903T170000Z DTSTAMP:20260423T035934Z UID:Inverse/15 DESCRIPTION:Title: Lorentzian Calderón problem under curvature bounds\nby Lauri Oksanen (University College London) as part of International Zoom Inverse Problem s Seminar\, UC Irvine\n\n\nAbstract\nWe introduce a method of solving inve rse boundary value problems for wave equations on Lorentzian manifolds\, a nd show that zeroth order coefficients can be recovered under certain curv ature bounds. The set of Lorentzian metrics satisfying the curvature bound s has a non-empty interior in the sense of smooth\, compactly supported pe rturbations of the metric\, whereas all previous results on this problem i mpose conditions on the metric that force it to be real analytic with resp ect to a suitably defined time variable. The analogous problem on Riemanni an manifolds is called the Calderón problem\, and in this case the known results require the metric to be independent of one of the variables. Our approach is based on a new unique continuation result in the exterior of t he double null cone emanating from a point. The approach shares features w ith the classical Boundary Control method\, and can be viewed as a general ization of this method to cases where no real analyticity is assumed. The talk is based on joint work with Spyros Alexakis and Ali Feizmohammadi.\n LOCATION:https://researchseminars.org/talk/Inverse/15/ END:VEVENT END:VCALENDAR