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Deformation Theory Seminar

Wednesday, December 4, 2019 - 2:00pm

Felix Wierstra

Grad Car CUNY


University of Pennsylvania


Check the time and room by the day before

In this talk I will describe the Eckmann-Hilton dual of the little disks algebra structure on iterated loop spaces: With the right definitions, every n-fold suspension is a coalgebra over the little n-disks operad. This structure induces non-trivial cooperations on the rational homotopy groups of an n-fold suspension. We describe the Eckmann-Hilton dual of the Browder bracket, which is a cooperation that forms an obstruction for an n-fold suspension to be an (n+1)-fold suspension, i.e. if this cooperation is non-zero then the space is not an (n+1)-fold suspension. This is joint work with José Manuel Moreno-Fernández.