Orateur: Livio Liechti (Université de Berne)
Titre:  Signature functions of positive knots .
Résumé: The first part of the talk is an introduction to the signature function, with emphasis on its relation to the Alexander polynomial and four-dimensional topology. In the second part, we compare signature functions of some classes of positive knots. In particular, we show that the signature function of quasi-rational knots with positive even weights is monotonic.

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