BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Melanie Graf (University of Tübingen) DTSTART:20211104T143000Z DTEND:20211104T153000Z DTSTAMP:20260423T023043Z UID:jomarec/12 DESCRIPTION:Title: Singularity theorems in low regularity\nby Melanie Graf (University o f Tübingen) as part of JoMaReC - Joint Online Mathematical Relativity Col loquium\n\n\nAbstract\nThe singularity theorems of R. Penrose and S. Hawki ng from the 1960s show that a spacetime satisfying certain physically reas onable curvature and causality conditions cannot be causal geodesically co mplete. Despite their great success these classical theorems still have so me drawbacks\, one of them being that they require smoothness of the metri c while in many physical models the metric is less regular. In my talk I w ill present work on singularity theorems based on distributional energy co nditions for metrics that are merely continuously differentiable – a reg ularity where one still has existence but not uniqueness for solutions of the geodesic equation. We will see that an approximation-based approach to the low-regularity issue is closely linked to establishing singularity th eorems under weakened energy conditions and while the improvements necessa ry are still entirely straightforward in the present case\, attempting to lower the regularity further would require some new methods.\n LOCATION:https://researchseminars.org/talk/jomarec/12/ END:VEVENT END:VCALENDAR