Speaker: Ana Cristina Castro Ferreira (University of Minho).
Title: Isometries of 3-Dimensional Semi-Riemannian Lie Groups.
When: Wednesday, May 6 at 4 pm UTC (check the time in your zone).
Abstract: Let G be a connected, simply connected three-dimensional Lie group (unimodular or non-unimodular) equipped with a left-invariant (Riemannian or Lorentzian) metric g. By definition, the isometry group Isom(G, g) contains G itself, acting by left translations. It turns out that, generically, Isom(G, g) is actually equal to G, and the natural question then becomes to classify those special metrics for which this is not the case. Using Lie-theoretical methods, we present a unified approach to obtain all pairs (G, g) whose full isometry group Isom(G, g) has dimension greater than or equal to four. As a consequence, we determine, for every pair (G, g), up to automorphism and scaling, the dimension of Isom(G, g), which can be three, four, or six. (Joint work with S. Chaib and A. Zeghib).


Zoom information:
Meeting ID: 894 736 351
Password: 533946
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