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Jean-Paul Allouche

(CNRS, LRI, Paris-Sud)

David Avis (McGill)

François Bergeron (UQÀM)

Rodney Canfield (Georgia)

Antoine Deza (McMaster)

Chris Godsil (Waterloo)

Penny Haxell (Waterloo)

Marni Mishna (Simon Fraser)

Patric Östergård

(TKK, Helsinki )

Sang-Il Oum

(KAIST, South Korea)

Frank Ruskey (Victoria)

Carla Savage

(NC State, Chair)

Jozsef Solymosi (UBC)

John Watrous (Waterloo)

Jason Brown (Dalhousie)

Pavol Hell (Simon Fraser)

Odile Marcotte (UQÀM, CRM)

Ortrud Oellermann (Winnipeg)

Daniel Panario

(Carleton, Chair)

Bruce Richter (Waterloo)

Srecko Brlek (UQÀM)

Gena Hahn (Montréal, Chair)

Benoit Larose

(Champlain Regional College,

Concordia)

Odile Marcotte (UQÀM, CRM)

Adrian Vetta (McGill)

TITRE / TITLE : On Graphs with Crossings

ORGANISATEUR / ORGANIZER : Michael O. Albertson (Smith College)

RÉSUMÉ / ABSTRACT : Studying graphs with crossings is one of the three classic relaxations of planarity. Early work on the crossing number focused on determining or bounding the crossing numbers of graphs within a given family. While there have been important recent advances along these lines, this minisymposium will consider what we can say about other graph properties, e.g. colorings, assuming that we know something about the crossings.

CONFÉRENCIERS / SPEAKERS: Dan Cranston (DIMACS and Bell Labs), Debra Boutin (Hamilton College), Sally Cockburn (Hamilton College), Daniel Kral (Charles University)

TITRE / TITLE : Complex Real-World Networks

ORGANISATEURS / ORGANIZERS : Anthony Bonato (Ryerson) and Jeannette Janssen (Dalhousie)

RÉSUMÉ / ABSTRACT : From the web graph to protein interaction networks, complex networks emerge in many disciplines. Recent research focuses on the modelling and mining of complex networks, using new and old techniques of graph theory to develop and analyze more accurate models. Such models simulate observed properties such as power law degree distributions and the small world property. We spotlight state-of-the-art research on complex networks, with applications to the computational, social, and biological sciences.

CONFÉRENCIERS / SPEAKERS : Jeannette Janssen, Jure Leskovec (Cornell), Allon Percus (UCLA), Natasa Przulj (UC Irvine), Raissa D'Souza (UC Davis)

TITRE / TITLE : Graph Classes and their Structures

ORGANISATEURS / ORGANIZERS : Andreas Brandstädt (Rostock) and Ortrud Oellermann (Winnipeg)

RÉSUMÉ / ABSTRACT : Structural characterizations of graph classes arise in a variety of contexts. Many interesting graph classes form subclasses of the perfect graphs or are extensions of subclasses of perfect graphs. In this minisymposium we will focus on problems relating to structural characterizations of graph classes and the complexity of recognition problems for known graph classes. The topics that will be discussed include (i) sunfree graphs, (ii) graphs that admit additive r-carcasses (special types of spanning trees), (iii) analogies between pentangulated and triangulated graphs, (iv) leaf powers of graphs, and (v) graph classes that form convex geometries relative to a new graph convexity property.

CONFÉRENCIERS / SPEAKERS : Chinh Hoang (Wilfrid Laurier), Feodor Dragan (Kent State), Terry McKee (Wright State), Andreas Brandstaedt, Ortrud Oellermann

TITRE / TITLE : Algebraic Graph Theory

ORGANISATEURS / ORGANIZERS : Sebastian Cioaba (Delaware) and Mike Newman (Ottawa)

RÉSUMÉ / ABSTRACT : This minisymposium examines the relationship between graph theory and algebra. In particular, many graph parameters or even in some cases the structure of a graph can be deduced from algebraic properties of various matrices associated with it. This has applications in areas as diverse as computer science, chemistry, network design, and coding theory. We will showcase recent results in Algebraic Graph Theory and their applications.

CONFÉRENCIERS / SPEAKERS : Sebastian Cioaba (Delaware), Karen Meagher (Regina), Randy Elzinga (Queen's), Jason Williford (Colorado at Denver), Mike Newman (Ottawa)

TITRE / TITLE : Degree Sequences in Graphs and Digraphs

ORGANISATEUR / ORGANIZER : Michael Ferrara (The University of Akron)

RÉSUMÉ / ABSTRACT : Degree sequences are one of the most elementary parameters of graphs and digraphs, yet a given (di)graphic sequence holds a great deal of information about its realizations. This notion has led many to study the properties and parameters shared by the realizations of a fixed (di)graphic sequence. This session addresses several such problems: graph classes characterized by their degrees, packings of degree sequences, Chvatal-type sufficient conditions, potentially H-graphic sequences and realizations of tournament score sequences.

CONFÉRENCIERS / SPEAKERS : Stephen Hartke (Nebraska at Lincoln), Arthur Busch (Dayton), Mike Ferrara (The University of Akron), John Schmitt (Middlebury College), Nathan Kahl (Seton Hall)

TITRE / TITLE : Broadcasting and Gossiping in Graphs

ORGANISATEUR / ORGANIZER: Hovhannes Harutyunyan (Concordia)

RÉSUMÉ / ABSTRACT : Broadcasting and gossiping are important message dissemination primitives in communication networks that also have applications in parallel algorithms and architecture. One of the main goals in this area is to find minimum time broadcast and gossip schemes (algorithms) for a given graph. Another important problem is to construct graphs with fewest edges that have a given broadcast or gossip time. Techniques of graph theory, combinatorics, and design and analysis of algorithms are used.

CONFÉRENCIERS / SPEAKERS : Stephen Hedetniemi (Clemson), Dana Richards (George Mason), Joseph Peters (Simon Fraser), Ke Qiu (Brock), Hovhannes Harutyunyan

TITRE / TITLE : Graph Pebbling

ORGANISATEURS / ORGANIZERS : Glenn Hurlbert (Arizona State) and Andrzej Czygrinow (Arizona State)

RÉSUMÉ / ABSTRACT : The area of graph pebbling is about 20 years old and was born from fundamental research in number theory. Since then it has been used to prove results in combinatorial group theory also. The subject is rapidly growing as more researchers become aware of its allure, challenging problems, and potential applicability. In this minisymposium we will discuss a wide range of interesting variations of pebbling, using various algebraic, probabilistic, and algorithmic tools, while sharing new results and conjectures.

CONFÉRENCIERS / SPEAKERS: Glenn Hurlbert (Arizona State), David Herscovici (Quinnipiac), Airat Bekmetjev (Hope College), Kevin Milans (Illinois at Urbana-Champaign), Anant Godbole (East Tennessee State University)

TITRE / TITLE : Linear Algebra in Combinatorics

ORGANISATEUR / ORGANIZER : Mahdad Khatirinejad (TKK Helsinki)

RÉSUMÉ / ABSTRACT : Combinatorics is a fundamental area in mathematics that often serves as a basis for many other disciplines. While in the past many results had been obtained by basic arguments, the current theory depends on more elaborate tools. Methods from linear algebra (such as dimension and eigenvalue arguments) are among the common, yet important and powerful, techniques due to which the study of combinatorics has been experiencing a remarkable growth.

CONFÉRENCIERS / SPEAKERS : Mahdad Khatirinejad (TKK Helsinki), Joel Friedman (UBC), Peter Dukes (Victoria), Kseniya Garaschuk (Victoria), Robert Craigen (Manitoba)

TITRE / TITLE : Constraint Satisfaction Problems

ORGANISATEURS / ORGANIZERS: Andrei Krokhin (Durham), Benoit Larose

(Concordia), and Claude Tardif (Royal Military College)

RÉSUMÉ / ABSTRACT : The Constraint Satisfaction Problems (CSP) is a general framework that generalizes many well-known combinatorial problems including graph colouring, homomorphism, and satisfiability. Since the CSP is computationally hard in general, much attention has recently been devoted to the task of identifying its subproblems that have low complexity or are solvable by a given polynomial-time algorithm. The minisymposium will present recent results in this direction that are based on techniques from universal algebra and graph theory.

CONFÉRENCIERS / SPEAKERS: Libor Barto (Charles University), Marcin Kozik (Jagellonian University), Andrei Bulatov (Simon Fraser University), Hubie Chen (UPF Barcelona) and Laszlo Egri (McGill University)

TITRE / TITLE : Colourings, Homomorphisms, and Beyond

ORGANISATEUR / ORGANIZER : Gary MacGillivray (Victoria), Jing Huang (University of Victoria) and Richard Brewster (Thompson Rivers University)

RÉSUMÉ / ABSTRACT : Colouring is arguably one of the most studied topics in graph theory. The natural generalization of colouring is graph homomorphisms, which has proved to be a fundamental concept. Every directed graph homomorphism problem is a constraint satisfaction problem (CSP), and conversely any CSP is equivalent to a directed graph homomorphism problem. This minisymposium features an overview of the broad area and four talks describing recent progress in the areas named in the title.

CONFÉRENCIERS / SPEAKERS : Richard Brewster (Thompson Rivers University), Ross Kang (McGill), Ruth Haas (Smith College), Nancy Clarke (Acadia), Jacobus Swarts (Victoria)

TITRE / TITLE : Graph Protection

ORGANISATRICE / ORGANIZER : Kieka Mynhardt (Victoria)

RÉSUMÉ / ABSTRACT : The term "graph protection" refers to a variety of concepts that involve guarding or defending the vertices or edges of graphs. It includes problems such as the firefighters problem, cops and robbers, the watchman problem, domination with stationary guards, domination with moving guards, and dominating broadcasts. The purpose of this minisymposium is to discuss some new developments in this area, e.g., domination in graph products, eternal domination with multiple guard moves, and dominating broadcasts.

CONFÉRENCIERS / SPEAKERS : Bert Hartnell (Saint Mary's), Stephen Benecke
(Victoria), Sarada Herke (Victoria), Ernie Cockayne (Victoria), Drago
Bokal (Maribor), Stephen Finbow (St. Francis Xavier)

TITRE / TITLE : Graph Theory with Applications I

ORGANISATRICE / ORGANIZER : Wendy Myrvold (Victoria)

RÉSUMÉ / ABSTRACT : This session and the following bring together researchers whose aim is to explore problems in graph theory and their applications in the two areas of topological graph theory and chemistry.

Part I: Use of the computer to discover graph theoretical conjectures; construction, visualisation, and embedding of graphs in surfaces.

CONFÉRENCIERS / SPEAKERS : Ermelinda DeLaVina (Houston), Gunnar Brinkmann (Ghent), Jack Graver (Syracuse), William Kocay (Manitoba), Jennifer Woodcock (Victoria)

TITRE / TITLE : Graph Theory with Applications II

ORGANISATEUR / ORGANIZER : Gilles Caporossi (HEC Montréal), Patrick Fowler (Sheffield)

RÉSUMÉ / ABSTRACT : This session and the previous one bring together researchers whose aim is to explore problems in graph theory and their applications in the two areas of topological graph theory and chemistry.

Part II: Applications to chemistry, especially the relations between graph-theoretical and physical properties of chemical graphs: stability, geometry, realizability, conductivity, reaction mechanisms.

CONFÉRENCIERS / SPEAKERS : Sean Daugherty (Victoria), Tomislav Doslic (Zagreb), Gilles Caporossi (HEC Montreal), Patrick Fowler (Sheffield), Douglas Klein (Texas A & M at Galveston)

TITRE / TITLE : Asymptotic Enumeration I

ORGANISATEUR / ORGANIZER : Daniel Panario (Carleton)

RÉSUMÉ / ABSTRACT : The talks in this double minisymposium (consisting of
Asymptotic Enumeration I and Asymptotic Enumeration II) present new
results for asymptotic enumeration problems in Combinatorics. Odlyzko's
survey in the Handbook of Combinatorics as well as the recent book by
extensive collections of methods and applications. The methods surveyed
there include elementary, probabilistic, and analytic techniques, and they
can be applied to graphs, partitions, permutations, as well as other
combinatorial objects. The talks in this session will cover both theory
and applications.

CONFÉRENCIERS / SPEAKERS : Edward A. Bender (UC San Diego), Rod Canfield (Georgia), Conrado Martínez (Universitat Politècnica de Catalunya),
Alfredo Viola (Universidad de la República), Daniel Panario (Carleton)

TITRE / TITLE : Asymptotic Enumeration II

CONFÉRENCIERS / SPEAKERS : Boris Pittel (Ohio State), Peter Cameron (Queen Mary College, University of London), Bruce Richmond (Waterloo), Alex Iosevich (Missouri), Jason (Zhicheng) Gao (Carleton)