January 28, 2008
10h30: *Establishing Non-D-finiteness of Combinatorial Generating Functions.* Marni Mishna, Simon Fraser University, BC, Canada.

Using the vehicle of a certain family of walks in the quarter plane we
illustrate the details of how the *iterated kernel method* can be used to establish that a generating function is not D-finite, thus proving
two of the three known classes of non-Dfinite walks in the quarter
plane. We shall discuss general (analytic, and combinatorial)
properties that might lead one to suspect that this is the case, and
examine other contexts where it arises, such as partitions with a
restricted number of crossings.
(work in collaboration with Andrew Rechnitzer, UBC)
.

Virginie Collette
Last modified: Mon May 23 18:32:54 CEST 2005