Schedule

Time Speaker / Event Title / Location
Sunday, July 3

5:00 - 7:00 WELCOME RECEPTION + REGISTRATION SFU HARBOUR CENTER
515 West Hastings Street
Segal Centre Conference Rooms 1400 - 1410
Monday, July 4

8:15 - 9:00 REGISTRATION Lobby: Goldcorp Center for the Arts
149 West Hastings Street
8:45 - 9:00 Welcome Message


Djavad Mowafaghian Cinema
(All talks will be in this room)
9:00 - 10:00
Plenary Lecture
Jason Bell (Waterloo)
Diagonals of rational power series and their uses in combinatorics, number theory, and computer science

Given a power series F(x_1,...x_d) = \sum f_{i_1,\,i_d} x_1^{i_1}...x_d^{i_d}, one can form a one-variable power series \Delta(F)(t) = \sum f_{n,n,...,n} t^n, called the diagonal of F. When F is the power series expansion of a rational function, the diagonal enjoys of F enjoys many nice properties, including satisfying a linear homogeneous differential equation with polynomial coefficients. Many natural generating functions arising in combinatorial enumeration can be expressed as diagonals and this fact often gives one a wealth of information about congruences of coefficients mod primes and asymptotic information. We give a survey of the theory of diagonals and discuss some more recent results and some of their applications to other areas of mathematics.

10:00 - 10:30 Torin Greenwood
Asymptotics of Bivariate Analytic Functions with Algebraic Singularities

10:30 - 11:00 COFFEE BREAK Room 2555
11:00 - 11:30 Art Duval, Bennet Goeckner, Caroline Klivans and Jeremy Martin
A non-partitionable Cohen-Macaulay simplicial complex
11:30 - 12:00 Seungjin Lee
Combinatorial description of the cohomology of the affine flag variety


12:00 - 2:00 LUNCH BREAK (Delegates are on their own)
2:00 - 3:00
Plenary Lecture
Jennifer Morse (Drexel University)
Discrete affairs with Macdonald and Gromov-Witten

After discussing the nature of problems in Schubert calculus, we will see how our lasting relationship with Macdonald symmetric functions has led us to find that Lascoux-Schützenberger charge on tableaux can be used as a tool in quantum, affine and equivariant Schubert calculus. We will also give a new formula for the monomial expansion of Macdonald polynomials using the charge statistic.

3:00 - 3:30 Maria Gillespie
A combinatorial approach to Macdonald q,t-symmetry via the Carlitz bijection

3:30 - 4:00 COFFEE BREAK Room 2555
4:00 - 4:30 Benjamin Young, Sara Billey and Alexander Holroyd
A bijective proof of Macdonald's reduced word formula

4:30 - 5:00 Edward Richmond and William Slofstra
Staircase diagrams and the enumeration of smooth Schubert varieties
5:30 - 7:00 POSTER SESSION A SFU HARBOUR CENTER
515 West Hastings Street
Segal Centre Conference Rooms 
Tuesday July 5

9:00 - 10:00
Plenary Lecture
Masato Okado (Osaka City University)
Crystal bases and rigged configurations

In my talk I will report on the present status of our project to understand a certain identity, called X=M, that has arisen in the end of the 20th century from the studies of combinatorial aspects of quantum integrable systems. Both sides of X=M are as simple as \sum_{b\in\mathcal{P}(B,\lambda)}q^{E(b)} = \sum_{\nu\in C(L(B),\lambda)}q^{c(\nu)}\prod_{a,i}{m^{(a)}_i+p^{(a)}_i\choose m^{(a)}_i}_q but what it implies is surprisingly deep. For instance, it is related to the following topics. Generalizing Lascoux-Schützenberger's charge and Schützenberger's involution to other root systems Mysterious combinatorial bijection due to Kerov-Kirillov-Reshetikhin. Calculating the number of irreducible modules in a tensor product of gl_n-modules of rectangular shapes. Closed formula for a branching function corresponding to a pair of affine Lie algebra and its underlying finite-dimensional simple Lie algebra. Linearizing a certain ultra-discrete nonlinear integrable system called box-ball system Geometric crystals introduced by Berenstein-Kazhdan and a solution to the Yang-Baxter equation by positive birational maps. For affine type A most (but not all!) topics are fairly well understood. However, apart from type A many conjectures are still waiting to be settled. For instance, item 2 of the above list was just worked out for type D only in this March. Taking this wonderful opportunity to talk at FPSAC meeting, I would like to persuade (especially young) people to join in this project.

10:00 - 10:30 Gabriel Frieden
Affine type A geometric crystal structure on the Grassmannian

10:30 - 11:00
COFFEE BREAK
11:00 - 11:30 Edward Allen, Joshua Hallam and Sarah Mason
Dual Immaculate Quasisymmetric Functions Expand Positively into Young Quasisymmetric Schur Functions

11:30 - 12:00 Maria Gillespie and Jake Levinson
Monodromy and K-theory of Schubert curves via generalized jeu de taquin

12:00 - 2:00 LUNCH BREAK  (Delegates are on their own)
2:00 - 3:00
Plenary Lecture
Margaret Readdy (University of Kentucky)
Polytopes and Beyond

Grünbaum and Shephard remarked that there were three developments which foreshadowed the modern theory of convex polytopes. The publication of Euclid's Elements and the five Platonic solids in 300 BC. Euler's formula in a 1750 letter to Goldbach which states that f_0 - f_1 + f_2 = 2 holds for any 3-dimensional polytope, where f_i is the number of i-dimensional faces. The discovery of polytopes in dimensions greater or equal to four by Schlafli in the 1850's. We will use these as a springboard to describe the theory of convex polytopes leading into the 21st century and beyond. Our survey will include recent results for flag enumeration of polytopes, Bruhat graphs, balanced digraphs, Whitney stratified spaces and quasi-graded posets.

3:00 - 3:30 Jose Samper
Relaxations of the matroid axioms I: Independence, Exchange and Circuits

3:30 - 4:00 COFFEE BREAK Room 2555
4:00 - 4:30 Yinghui Wang and Richard Stanley
The Smith normal form distribution of a random integer matrix

4:30 - 5:00 Olivier Bernardi, Mireille Bousquet-Mélou and Kilian Raschel
Counting quadrant walks via Tutte's invariant method
5:30 - 7:00 POSTER SESSION B SFU HARBOUR CENTER
515 West Hastings Street
Segal Centre Conference Rooms 1400 - 1410
Wednesday July 6

9:00 - 10:00
Plenary Lecture
Mike Steel (University of Canterbury) Formal power series and combinatorial methods in phylogenetics

Phylogenetics is the reconstruction and analysis of evolutionary trees in systematic biology and other areas of classification (e.g. historical linguistics, epidemiology). The mathematics that underlies this field is based on combinatorics and discrete random processes. In this talk, I will highlight both established and recent phylogenetic applications of familiar combinatorial techniques that have proved useful for deriving new results on phylogenetic trees. In particular, I will describe how: exponential generating functions for trees and forests can be used (together with Menger's theorem and multivariate Lagrange inversion) to enumerate phylogenies under a `minimal evolution' score; every binary phylogenetic tree can be realized as a unique `perfect phylogeny' with just four functions (`characters') from the leaf set of the tree into an infinite discrete state space; the probabilistic method provides an O(n^alpha) (for any alpha less than one) analog of the last result when the state space is finite and the tree has n leaves. extended Pólya urn models are relevant to speciation-extinction models that `evolve' phylogenetic trees.

10:00 - 10:30 Olya Mandelshtam and Xavier Viennot
Rhombic alternative tableaux, assembl\'{e}es of permutations, and the ASEP
10:30 - 11:00 COFFEE BREAK Room 2555
11:00 - 11:30 Aram Dermenjian, Christophe Hohlweg and Vincent Pilaud
The facial weak order in finite Coxeter groups
11:30 - 12:00 Christian Stump, Hugh Thomas and Nathan Williams
Cataland: Why the Fuss?
12:00 -- FREE TIME / EXCURSION (Excursion attendees, please meet the bus at 12:30)
Thursday, July 7

9:00 - 10:00
Plenary Lecture
Ben Brubaker (University of Minnesota)
Explicit formulas for special functions: crystal bases, ice models, and Iwahori-Hecke algebras

We discuss various ways of obtaining explicit expressions for symmetric functions and their deformations, which are often realized as matrix coefficients for p-adic groups. The three methods featured are statistical mechanics (two-dimensional lattice models), crystal bases for highest weight representations, and symmetrizers in Iwahori-Hecke algebras.

10:00 - 10:30 Luigi Cantini, Jan DeGier and Michael Wheeler
Matrix product and sum rule for Macdonald polynomials
10:30 - 11:00 COFFEE BREAK
11:00 - 11:30 Greg Muller and David Speyer
The twist for positroids
11:30 - 12:00 Angele Hamel and Ronald King
Factorial Characters and Tokuyama's Identity for Classical Groups

12:00 - 2:00 LUNCH BREAK
2:00 - 3:00
Plenary Lecture
Federico Ardila (San Francisco State University)
The algebraic and combinatorial structure of generalized permutahedra

Generalized permutahedra are a beautiful family of polytopes which are known to have a rich combinatorial structure. We explore the Hopf algebraic structure of this family, and use it to unify old results, prove new results, and answer open questions about families of interest such as graphs, matroids, posets, trees, set partitions, building sets, hypergraphs, and simplicial complexes. The talk will be based on joint work with Marcelo Aguiar, and will assume no previous knowledge of Hopf algebras or generalized permutahedra.

3:00 - 3:30 Thibault Manneville and Vincent Pilaud
Compatibility fans realizing graphical nested complexes

3:30 - 4:00 COFFEE BREAK Room 2555
4:00 - 4:30 Chris Fraser
Quasi-isomorphisms of cluster algebras and the combinatorics of webs
4:30 - 5:00 Diane Maclagan and Felipe Rincon
Tropical Ideals
6:30 -- BANQUET Rogue Wetbar - Convention Center location 200 Burrard St, Vancouver, Vancouver 
Friday, July 8

9:00 - 10:00
Plenary Lecture
Jozsef Solymosi (University of British Columbia)
Geometric Incidences in Combinatorics

What is the maximum number of incidences determined by n points and m lines? The answer to this question is often hard to find depending on the underlining field and other possible constraints. On the other hand such questions arise naturally from various fields of mathematics and computer science, so it is important to understand incidence structures with high incidence numbers. I will mention some recent breakthrough results and many open problems.

10:00 - 10:30 Roger Behrend, Ilse Fischer and Matjaz Konvalinka
Diagonally and antidiagonally symmetric alternating sign matrices of odd order
10:30 - 11:00 COFFEE BREAK Room 2555
11:00 - 11:30 Valentin Féray
Cyclic inclusion-exclusion and the kernel of P-partitions
11:30 - 12:00 Shuhei Kamioka
A triple product formula for plane partitions derived from biorthogonal polynomials
12:00 - 2:00 LUNCH BREAK (Delegates on their own)
2:00 - 2:30 Pavel Galashin, Darij Grinberg and Gaku Liu
Refined dual stable Grothendieck polynomials and generalized Bender-Knuth involutions
2:30 - 3:00 Scott Andrews, and Nathaniel Thiem
The generalized Gelfand--Graev characters of $\mathrm{GL}_n(\mathbb{F}_q)$
3:00 - 3:30 Élie de Panafieu
Counting connected graphs with large excess
3:30 - 4:00 COFFEE BREAK Room 2555
4:00 - 4:10 

FPSAC STUDENT PRIZE FOR BEST PAPER
4:10 - 5:10
Plenary Lecture
Guillaume Chapuy
(CNRS/ Universite Paris-Diderot)
Counting Maps on Surfaces

I will talk about maps, which are graphs embedded on surfaces. The enumeration of maps was initiated in the 1950's by Tutte, who discovered that planar maps (when the surface is the sphere) are counted by beautiful formulas. This was just the beginning of a story that is still developing today and has connections to almost every part of combinatorics. The question of understanding how the enumerative properties of maps depend on the genus g >= 0 of the underlying surface is especially interesting. Very strong results can be proved, coming from a variety of techniques, from representation theory of the symmetric group, to generatingfunctionology, integrable systems and tau-functions, or bijective combinatorics. However we still lack a general theory encapsulating all these results together. The look for a unification raises many questions and challenges for each of the tools involved. In this talk I will show some of these results and some of these connections.
5:10 - 5:15  LONDON 2017
Subpages (1): Poster Sessions
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