Montag,
2012-10-22
16:15 Uhr
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Raum 404, Eckerstr. 1
siehe Eröffnungskolloquium des Graduiertenkollegs:
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Montag,
2012-10-29
16:15 Uhr
|
Raum 404, Eckerstr. 1
NN:
NN
Programmdiskussion |
Montag,
2012-11-05
16:15 Uhr
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Raum 404, Eckerstr. 1
Sebastian Goette:
Fibrewise Morse functions and higher torsion invariants
I will give a short overview about higher torsion invariants
for families of compact manifolds. Then I will sketch a generalisation of Igusa-Klein torsion that has similar properties as Bismut-Lott torsion. This is the first step in the comparison of the two invariants. |
Montag,
2012-11-12
16:00 Uhr
|
Raum 404, Eckerstr. 1
Oliver Fabert:
Floer theory and Gromov-Witten theory
In his proof of the Arnold conjecture about the number of fixed points of Hamiltonian symplectomorphisms, A. Floer developed a new infinite-dimensional version of Morse homology. While the chain groups are generated by these fixed points, the differential counts pseudoholomorphic sections, which in turn provides a link to Gromov-Witten theory. In my talk I will introduce the basic concepts of Floer homology and its application to the Arnold conjecture. At the end I plan to sketch the main results of my recent paper 1206.1564, where I was able to complete the correspondence between rational Gromov-Witten theory and Floer theory of symplectomorphisms. |
Montag,
2012-11-19
16:15 Uhr
|
Raum 404, Eckerstr. 1
kein Vortrag:
(Dozentenversammlung) |
Montag,
2012-11-26
16:15 Uhr
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Raum 404, Eckerstr. 1
Alex Koenen:
Introduction to Vafa-Witten Estimates
1984 Vafa and Witten developed a method to obtain upper bounds for the first eigenvalue of a Dirac-Operator on a compact manifold. I will explain the method and the related geometry in detail. We will see an example of an optimal Vafa-Witten bound on the projective space obtained by geometric arguments.
Furthermore, I will give a connection between the Vafa-Witten method and L-infinity variational problems. |
Montag,
2012-12-03
16:15 Uhr
|
Raum 404, Eckerstr. 1
Alexander Alexandrov:
Free fermions and tau-functions
The formalism of free fermions
used for construction of tau-functions of classical
integrable hierarchies is reviewed.
We give a derivation of
group-like properties of the normally ordered exponents,
transformations between different normal orderings,
the bilinear identity and the generalized Wick's
theorem. We also consider various examples of tau-functions
and give their fermionic realization. |
Montag,
2012-12-10
16:00 Uhr
|
Raum 404, Eckerstr. 1
Ilarion Melnikov (MPI Potsdam-Golm):
First order deformations in heterotic compactifications
-- Vortrag im Rahmen des SFB Transregio 71 --
Many beautiful geometric structures, such as Calabi-Yau (CY) manifolds and their moduli spaces, arise naturally in the context of string theory. In heterotic string theory a generalization of CY geometry is given by holomorphic vector bundles over CY spaces. This talk is concerned with more general heterotic geometries: vector bundles over complex but typically non-Kaehler manifolds. I will review this geometric structure and its origin in string theory and then focus on a characterization of the first order deformation space of these geometries.
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Montag,
2012-12-17
16:15 Uhr
|
Raum 404, Eckerstr. 1
Hartmut Weiß (LMU München):
Geometric flows and special holonomy
Vortrag im Rahmen des SFB Transregio 71
Metrics with holonomy contained in G_2 on a 7-manifold are
induced by so-called positive 3-forms which are torsionfree, i.e. satisfy a
certain nonlinear 1st order PDE. I will discuss a parabolic flow on
positive 3-forms whose stationary points are precisely given by the
torsionfree ones. This is joint work with F. Witt.
If time permits I will describe a generalization to a spinorial setting
(joint with B. Ammann and F. Witt). |
Montag,
2013-01-07
16:15 Uhr
|
Raum 404, Eckerstr. 1
Dr.Blaz Mramor:
Laminations of solutions in the Frenkel-Kontorova model with weak coupling
Vortrag im Rahmen des SFB TR 71 |
Montag,
2013-01-21
16:15 Uhr
|
Raum 404, Eckerstr. 1
Svenja Dahms:
Adiabatic limit of the Ray-Singer torsion |
Montag,
2013-01-28
16:15-17:15 Uhr
|
Raum 404, Eckerstr. 1
Anda Degeratu:
Analysis on crepant resolutions of Calabi-Yau orbifolds
A Calabi-Yau orbifold is locally modeled on C^n/G with G a finite subgroup of SU(n). If the singularity is isolated, then the crepant resolution (if it exists) is an ALE manifold, for which index-type results are well known. However, most of the time the singularity is not isolated, and for the corresponding crepant resolution there is no index theorem so far. In this talk, I present the first step towards obtaining such a result: I will introduce the class of iterated cone-edge singular manifolds and the corresponding quasi-asymptotically conical spaces (for which orbifolds and their crepant resolutions are an example), and build-up the general set-up for studying Fredholm properties of geometrical elliptic operators on these spaces. This is joint work with Rafe Mazzeo.
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Montag,
2013-02-04
16:15 Uhr
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Raum 404, Eckerstr. 1
Nena Röttgen:
Closed Geodesics on Open Manifolds with Convex Ends |
Montag,
2013-02-11
16:15 Uhr
|
Raum 404, Eckerstr. 1
Emanuel Scheidegger:
Special Kähler geometry
I will give an introduction to special Kähler structures and some of their aspects. A special Kähler structure is a connection on the tangent bundle of a Kähler manifold with a number of "special" properties. They appear naturally in the context of certain integrable systems and of moduli spaces of Calabi-Yau threefolds. |
