Relativity Seminar
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Tue, 22/01/2008 11:00 |
Paul Tod (Oxford) |
Relativity Seminar  |
L3 |
| One knows, for example by proving well-posedness for an initial value problem with data at the singularity, that there exist many cosmological solutions of the Einstein equations with an initial curvature singularity but for which the conformal metric can be extended through the singularity. Here we consider a converse, a local extension problem for the conformal structure: given an incomplete causal curve terminating at a curvature singularity, when can one extend the conformal structure to a set containing a neighbourhood of a final segment of the curve? We obtain necessary and sufficient conditions based on boundedness of tractor curvature components. (Based on work with Christian Luebbe: arXiv:0710.5552, arXiv:0710.5723.) | |||
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Tue, 12/02/2008 11:00 |
Frank Pacard (Paris XII) |
Relativity Seminar |
L3 |
| : I will review various constructions and properties of complete constant scalar curvature metrics. I will emphasize the role played by the so called "Fowler's solutions" which give rise to metrics with cylindrical ends. I will also draw the parallel between these constructions and similar constructions which surprisingly (or not) appear in a different context : constant mean curvature surfaces and more recently the Allen-Cahn equation and some equation in the biological theory of pattern formation. | |||
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Tue, 19/02/2008 11:00 |
Professor Robert Beig (Vienna University) |
Relativity Seminar |
L3 |
| We outline a method to solve the stationary Einstein equations with source a body in rigid rotation consisting of elastic matter. This is work in progress by R.B., B.G.Schmidt, and L.Andersson | |||
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Tue, 04/03/2008 11:00 |
Hans Ringstroem (Royal Institute of Technology, Stockholm) |
Relativity Seminar |
L3 |
| In the case of Einstein's equations coupled to a non-linear scalar field with a suitable exponential potential, there are solutions for which the expansion is accelerated and of power law type. In the talk I will discuss the future global non-linear stability of such models. The results generalize those of Mark Heinzle and Alan Rendall obtained using different methods. | |||
