The University of Arizona

Please note that this event has ended!

Super Ptolemy Relation and Double Dimer Covers

Algebra and Number Theory Seminar

Super Ptolemy Relation and Double Dimer Covers
Series: Algebra and Number Theory Seminar
Location: ENR2-S395
Presenter: Nicholas Ovenhouse, Yale

Given a quadrilateral inscribed in a circle, Ptolemy's Theorem relates the lengths of the diagonals and sides. In general, for an inscribed polygon, Ptolemy's relation allows one to write the length of any diagonal as a Laurent polynomial in terms of the lengths of the diagonals coming from some fixed triangulation. Schiffler and Musiker showed that these Laurent polynomials can be written in terms of perfect matchings (or "dimer covers") of some planar graph. Recently, Penner and Zeitlin defined a super-symmetric version of Ptolemy's relation, involving anti-commuting variables. In recent work with Musiker and Zhang, we showed that iterated applications of the super Ptolemy relation gives a sum over double dimer covers of the same planar graph.