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Monday, 2013-04-15 16:15 |
Raum 404, Eckerstr. 1 NN: Programmdiskussion |
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Monday, 2013-04-22 16:15 |
Raum 404, Eckerstr. 1 Victor Bangert: Closed currents and measured laminations |
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Monday, 2013-04-29 16:15 |
Raum 404, Eckerstr. 1 Björn Mützel (Montpellier): Construction of Riemann surfaces with large systoles |
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Monday, 2013-05-06 16:15 |
Raum 404, Eckerstr. 1 Sebastian Goette: L^2 index theory for families |
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Monday, 2013-05-13 16:15 |
Raum 404, Eckerstr. 1 Katharina Heuser: Hasse-Weil L-function of elliptic curves over Q and beyond |
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Monday, 2013-05-27 17:15 |
Hörsaal 2, Physik Hochhaus, Hermann-Herder-Straße 3 Das Oberseminar Differentialgeometrie entfällt wegen der Antrittsvorlesung von Herrn Juniorprofessor Dr. Harald Ita um 17:15 im Großen HS des Physikalischen Institutes. |
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Monday, 2013-06-10 16:15 |
Raum 404, Eckerstr. 1 Magnus Engenhorst: Dimer models and toric geometry |
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Monday, 2013-06-17 16:15 |
Raum 404, Eckerstr. 1 Katrin Wendland: The elliptic genus of K3 Elliptic genera have been introduced and studied in the late 80s, on the one hand in topology in the context of circle actions on manifolds, and on the other hand in physics in the context of Dirac-like operators on loop spaces. The elliptic genus of a Calabi-Yau manifold X is a modular function which interpolates between some of the known topological invariants of X. A two-variable version of the elliptic genus was suggested by Witten in the mid 90s, which most naturally arises as an invariant of superconformal field theories associated to X, and which encorporates almost all other versions of the elliptic genus as specializations. The precise relations between the conformal field theorists' and the topologists' approaches to the elliptic genus have subsequently been clarified by Malikov/Schechtman/Vaintrob, by Borisov/Libgober, and by Kapustin. The talk will first give an overview on the construction of the elliptic genus for Calabi-Yau manifolds X. Then specific properties of the elliptic genus for K3 surfaces X will be discussed, including a number of open conjectures related to the so-called "Mathieu Moonshine Phenomenon" for the elliptic genus of K3. |
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Monday, 2013-06-24 16:15 |
Raum 404, Eckerstr. 1 Arkadi Schelling: The Topological eta-Invariant |
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Monday, 2013-06-24 16:15 |
Raum 404, Eckerstr. 1 Arkadi Schelling: The Topological eta-Invariant The talk is based on the paper "On the Topological Contents of eta-Invariants" by Ulrich Bunke. The eta-invariant can be defined on twisted Dirac-operators over Spin^c-manifolds and it fulfills certain index-theorems. First, the talk will show a way to derive a bordism invariant from these theorems and, second, use the Pontrjagin-Thom construction and homotopy theory to construct a bordism invariant by topological means. The talk will state that the two invariants coincide, but won't prove this statement. See also: http://arxiv.org/abs/1103.4217 |
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Monday, 2013-07-01 16:15 |
Raum 404, Eckerstr. 1 Johannes Frank: Gauss-Bonnet-Theorem for measured laminations |
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Monday, 2013-07-08 16:15 |
Raum 404, Eckerstr. 1 Felix Grimm: CFT via the Ising Model |
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Monday, 2013-07-15 16:15 |
Raum 404, Eckerstr. 1 Emanuel Scheidegger: Spezielle Kähler Geometrie, Quasimodulformen, und topologische Stringtheorie Basierend auf der Einführung in spezielle Kähler Geometrie im letzten Semester betrachten wir Parameterräume komplexer Strukturen von Calabi-Yau-Mannigfaltigkeiten der Dimension 3. Diese Parameterräume sind projektiv speziell Kähler. Es gibt einen differentiellen Polynomring in den Schnitten der Vektorbündel, die natürlich zu einer projektiven speziellen Kähler Mannigfaltigkeit assoziiert sind. Dieser Ring hat eine ähnliche Struktur wie der Ring der Quasimodulformen. Bei geeigneter Wahl der Calabi-Yau-Mannigfaltigkeit sind die beiden Ringe isomorph. Dies führt zu einer neuen Dualität in topologischer Stringtheorie. |