Cohomology rings of regular nilpotent Hessenberg varieties and hyperplane arrangements

Satoshi Murai, Waseda University
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via Zoom

Note: This talk begins with a pre-seminar (aimed at graduate students) at 3:30–4:00. The main talk starts at 4:10.

Join Zoom Meeting: https://washington.zoom.us/j/95020884635
Meeting ID: 950 2088 4635

An ideal arrangement is a hyperplane arrangement defined by a lower
ideal in the poset of positive roots of a root system. This arrangement
is known to have a close connection to a regular nilpotent Hessenberg
variety. In this talk, I will show that we can compute the cohomology
ring of a regular nilpotent Hessenberg variety from the logarithmic
derivation module of ideal arrangement. It time allows, I will also
talks about monomial basis of these cohomology rings in type A. The talk
is based on a joint work with T. Abe, T. Horiguchi, M. Masuda, T. Sato
and a joint work with M. Harada, Horiguchi, M. Precup and J. Tymoczko.