Deformations of log-canonical Poisson brackets with an open T-leaf

by Mykola Matviichuk: (MPIM)

Thursday Apr 24, 2025, 3:00 PM → 4:00 PM Europe/Berlin

MPIM, Vivatsgasse, 7 - Lecture Hall (Max Planck Institute for Mathematics)

MPI-Oberseminar

A log-canonical Poisson bracket is one of the form {x_i,x_j} = lambda_{ij} x_i x_j. Assuming there exists an action of an algebraic torus T that preserves the bracket and admits an open T-leaf (i.e. an open T-orbit of a symplectic leaf), I will describe all T-invariant Poisson deformations of { , }. The key result here is an unobstructedness phenomenon akin to the Bogomolov-Tian-Todorov theorem in the deformation theory of Calabi-Yau manifolds. Time permitting, I will discuss applications of this deformation-theoretic approach to the Poisson brackets on Bott-Samelson varieties and Poisson CGL extensions in the sense of Goodearl-Yakimov. This is joint work with Jiang-Hua Lu.