BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Velichka Milousheva (Institute of Mathematics and Informatics\, Bu lgarian Academy of Sciences\, Bulgaria) DTSTART:20201211T120000Z DTEND:20201211T125000Z DTSTAMP:20260423T004136Z UID:WMSEE/7 DESCRIPTION:Title: Ma rginally trapped (quasi-minimal) surfaces in pseudo-Euclidean 4-spaces \nby Velichka Milousheva (Institute of Mathematics and Informatics\, Bulga rian Academy of Sciences\, Bulgaria) as part of Women in Mathematics in So uth-Eastern Europe\n\n\nAbstract\nA surface in a pseudo-Riemannian manifol d is called quasi-minimal if its mean curvature vector is lightlike at eac h point of the surface. When the ambient space is the Lorentz-Minkowski sp ace\, the quasi-minimal submanifolds are also called marginally trapped – a notion borrowed from General Relativity. The concept of trapped surf aces was first introduced by Sir Roger Penrose in 1965 in connection with the theory of cosmic black holes.\n\nMarginally trapped surfaces in spacet imes satisfying some extra conditions have recently been\nintensively stud ied in connection with the rapid development of the theory of black holes in Physics. Most of the results give a complete classification of marginal ly trapped surfaces under some additional geometric conditions\, such as h aving positive relative nullity\, having parallel mean curvature vector fi eld\, having pointwise 1-type Gauss map\, being invariant under spacelike rotations\, under boost transformations\, or under the group of screw rota tions.\n\nQuasi-minimal surfaces in the pseudo-Euclidean 4-space with neut ral metric satisfying some additional conditions have also been studied ac tively in the last few years. Most of the results are due to Bang-Yen Chen and his collaborators.\n\nIn this talk we will give an overview of these classification results and present the Fundamental existence and uniquenes s theorem for the general class of quasi-minimal Lorentz surfaces in the p seudo-Euclidean 4-space with neutral metric.\n LOCATION:https://researchseminars.org/talk/WMSEE/7/ END:VEVENT END:VCALENDAR