Date et heure : lundi 6 février 17h00 Lieu : salle B014, Calais Burglind Jöricke (actuellement IHES) "Braids, conformal module and algebroid functions" Résumé : -------- After a brief introduction to the theory of braids I will discuss a conformal invariant of braids. For a closed braid it is defined as the supremum of conformal modules in the sense of Ahlfors of certain annuli associated to the closed braid. This invariant is related to the entropy of braids. Very roughly speaking, the conformal module gives obstructions for smooth objects which involve braids, to be realizable by the respective holomorphic objects. I will give examples concerning algebroid functions (i.e. multivalued analytic functions) on open Riemann surfaces.