Prochainement

Pas d'événement prévu ce mois

Passés

Mercredi 4 mars 14:00-15:00 Ksenia Fedosova  (Université de Freiburg)
Selberg zeta function twisted by representations with non-expanding cusp monodromy

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Lieu : Salle 3L8

Résumé : To a hyperbolic surface and a finite-dimensional representation of its fundamental group, we associate a Selberg zeta function. The main goal of the talk is to show that under the condition that the representations have non-expanding cusp monodromy (that in particular implies that such representations need not be unitary), the Selberg zeta function exists and admits a meromorphic extension to the whole complex plane. We will also show that outside this class of representations, the Selberg zeta function does not converge.

Selberg zeta function twisted by representations with non-expanding cusp monodromy  Version PDF

Mercredi 26 février 14:00-17:00 Nicoletta Tardini  (Université de Turin)
Special Hermitian metrics on complex manifolds

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Lieu : Salle 3L8

Résumé : A very special class of complex manifolds is realized by Kähler manifolds, namely complex manifolds admitting a Hermitian metric whose fundamental form is symplectic. The existence of such a metric implies sev- eral cohomological obstructions as the validity of the ∂∂-lemma. We will discuss the relations between this property and the Bott-Chern cohomol- ogy on complex non-Kähler manifolds. Moreover, several generalizations of Kähler metrics have been introduced by imposing that the fundamental form of a Hermitian metric (or its powers) is in the kernel of a suitable differential operator. One could expect that these metrics arise as critical points of naturally defined functionals on the space of Hermitian metrics. We will investigate some of these functionals, restricted to a conformal class of normalized Hermitian metrics, discussing the geometric meaning of their critical points. These are joint works with Daniele Angella, Nicolina Istrati and Alexandra Otiman.


Special Hermitian metrics on complex manifolds  Version PDF