On quasimorphisms invariant under automorphisms

Prelegent(ci)

Jarek Kędra

Afiliacja

University of Aberdeen

Termin

8 czerwca 2021 16:30

Informacje na temat wydarzenia

Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))

Seminarium

Seminarium „Topologia algebraiczna”

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Quasimorphisms comprise a good function theory on groups and many groups
admits an abundance of them. It was recently discovered by Brandenbursky and
Marcinkowski that the free group on two generators admits a quasimorphism
that is invariant under all automorphisms of F_2. I will present a more
recent construction, due to Bastien Karlhofer, of aut-invariant
quasimorphisms on various free products and graph products of groups.
Examples include groups like SL(2,Z), the braid group on three hair some
right angled Artin and Coxeter groups.

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