Geometry/Physics Seminar

Title: Quantum cluster algebras from geometry
Speaker: Leonid Chekhov
Speaker Info: Steklov Institute, Moscow
Brief Description:

We identify the Teichmuller space $T_{g,s,n}$ of (decorated) Riemann surfaces $\Sigma_{g,s,n}$ of genus $g$, with $s>0$ holes and $n>0$ bordered cusps located on boundaries of holes uniformized by Poincare with the character variety of $SL(2,R)$-monodromy problem. The effective combinatorial description uses the fat graph structures; observables are geodesic functions of closed curves and $\lambda$-lengths of paths starting and terminating at bordered cusps decorated by horocycles. Such geometry stems from special "chewing gum" moves corresponding to colliding holes (or sides of the same hole) in a Riemann surface with holes. We derive Poisson and quantum structures on sets of observables relating them to quantum cluster algebras of Berenstein and Zelevinsky. A seed of the corresponding quantum cluster algebra corresponds to the partition of $\Sigma_{g,s,n}$ into ideal triangles, $\lambda$-lengths of their sides are cluster variables constituting a seed of the algebra; their number $6g-6+3s+2n$ (and, correspondingly, the seed dimension) coincides with the dimension of $SL(2,R)$-character variety given by $[SL(2,R)]^{2g+s+n-2}/\prod_{i=1}^n B_i$, where $B_i$ are Borel subgroups associated with bordered cusps.

The talk is based on the joint papers with with M.Mazzocco and V.Roubtsov

Date: Tuesday, January 17, 2017
Time: 1:00pm
Where: Lunt 103
Contact Person: Ezra Getzler
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