Which Hessenberg varieties are GKM?

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Julianna Tymoczko, Smith College

Online Talk 

Zoom link: https://princeton.zoom.us/j/92116764865

Passcode: 114700

GKM theory is the name given to an algebraic-combinatorial model that describes the torus-equivariant cohomology of suitable spaces.  To apply GKM theory, we typically need a variety whose geometry is structurally encoded by combinatorics, like flag varieties and their subvarieties.  Hessenberg varieties are an important family of subvarieties of the flag variety.  We give conditions under which certain Hessenberg varieties are GKM (or not) with respect to various torus actions.  Time permitting, we also sketch some related results about the underlying geometry of Hessenberg varieties.  This work is joint with Rebecca Goldin.