Ursula Hamenstädt

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In the paper [B-C-G] Besson, Courtois and Gallot proved the following remarkable theorem: Let S be a closed rank 1 locally symmetric space of noncompact type and let M be a closed manifold of negative curvature which is homotopy equivalent to S. If S and M have the same volume and the same volume entropies (i.e. the same asymptotic growth rate of volumes of(More)
Let T (S) be the Teichmüller space of an oriented surface S of finite type. We discuss the action of subgroups of the mapping class group of S on the CAT(0)-boundary of the completion of T (S) with respect to the Weil-Petersson metric. We show that the set of invariant Borel probability measures for the Weil-Petersson flow on moduli space which are(More)
Angefertigt mit der Genehmigung der Mathematisch-Summary This thesis consists of four parts all of which deal with different aspects of Hodge classes on self-products of K3 surfaces. In the first three parts we present three different strategies to tackle the Hodge conjecture for self-products of K3 surfaces. The first approach is of deformation theoretic(More)
Let S be a closed oriented surface S of genus g ≥ 0 with m ≥ 0 marked points (punctures) and 3g − 3 + m ≥ 2. This is a survey of recent results on actions of the mapping class group of S which led to a geometric understanding of this group. Mathematics Subject Classification (2010). Primary 30F60, Secondary 20F28, 20F65, 20F69