Buongiorno,

Siete invitati al seminario di geometria di domani (c'è purtroppo una sovrapposizione con un altro seminario in Normale di cui mi accorgo solo ora... ).

A presto, Bruno Martelli

16-May-2018 - 15:30 Sala Seminari (Dip. Matematica) http://www.dm.unipi.it/webnew/it/aula/sala-seminari-dip-matematica Pretzel links, mutation, and the slice-ribbon conjecture http://www.dm.unipi.it/webnew/it/seminari/pretzel-links-mutation-and-slice-ribbon-conjecture Paolo Aceto

We show that the mutant 2-component pretzel links P(p,q,-q,-p) and P(p,q,-p,-q) are not concordant for any distinct odd integers p and q greater than 1. As a corollary, we obtain a proof of the slice-ribbon conjecture for 4-stranded 2-component pretzel links. In order to distinguish mutant links up to concordance we consider 3-fold branched covers and use an obstruction based on Donaldson's diagonalization theorem. This is joint work with Min Hoon Kim, JungHwan Park and Arunima Ray.