Algebraic Combinatorics Seminar

Thursday, May 17, 2018 11:30 am - 11:30 am EDT (GMT -04:00)

Title: Asymptotic Distribution of Parameters in Random Maps

Speaker: Julien Courtiel
Affiliation: Universite de Caen in France
Room: MC 6486

Abstract: A rooted map is a connected graph in which the half-edges have
been cyclically ordered around each vertex. This talk addresses the
question of the asymptotic behavior of several parameters of maps (such
as number of vertices, the root degree) without any constraint on the
genus of the maps. Although this perspective is quite opposed to the
classical one where maps model discrete surfaces (and so where the genus
is important), this has numerous applications in transverse scientific
areas, like Quantum Field Theory or lambda-calculus.

Thus, as a motivation, we begin by introducing the existing connexions
between combinatorial maps and other families of objects. Then, we
explain the (new!) techniques required to solve the underlying
enumerative problem, and show why they must differ from the ones used
when the genus is fixed. Finally, we stand back a bit, and ask ourselves
whether the asymptotic results could have been thought ahead, given the
previously mentioned combinatorial connexions.

This is a joint work with Olivier Bodini, Sergey Dovgal and Hsien-Kuei
Hwang.