Events

The Matching Polynomial of a Graph

Abstract:

If  p(G,k) denotes the number of matchings of size k in the graph G and  n=|V(G)|, then the matching polynomial of G is

m(G,t) = \sum_k   p(G,k) (-1)^k t^{n-2k}.

Characterizations of Non-Seymour Graphs

Abstract: 

A graph is called Seymour if for every join F there exists a complete packing of F-cuts. Bipartite graphs and series-parallel graphs are Seymour, by two results of Seymour, of course.

The fundamental mandate of the workshop, co-organized by Professors Tom Coleman and Michele Mosca, is to provide a forum for both scientific presentations and discussion of issues related to quantum optimization. Optimization researchers will learn about the quantum technology and methodologies and the quantum researchers will learn about hard optimization problems that may yield to quantum optimization approaches.

Combinatorial Positivity in the Schubert Calculus via Dual Equivalence Graphs

Abstract:

Algebraic geometry poses many positivity challenges to enumerative combinatorics. Two notable such challenges are Macdonald's positivity conjecture, and structure constants in the Schubert Calculus.

A Set-Theoretic Approach to Fractional Iterates

Abstract:

This talk relates to an early excursion of Bill Tutte into professional level mathematics. The connection will be explained in the talk.

A Brief History of Cutting Plane Methods

Abstract:

We will cover the story of MIP cutting planes from their roots with Gomory's cutting plane algorithm to the more recent developments like multirow cuts. Along the way are topics including corner relaxations, disjunctive programming and lift-and-project.

Promotion for Staircase Tableaux

Abstract:

Promotion is one of the fundamental operations on standard young tableaux. It has received a fair bit of attention recently because of its relevance in representation theory, and its intriguing combinatorial structure.

Sylvester's 4-point problem and straight line drawings of the complete graph K_n

Abstract: In the 1880's, Sylvester raised the following question: if we
pick 4 points at random from the Euclidean plane, what is the probability
that they make a convex quadrilateral? Equivalently, what is the

While the Size of Subgraphs Grows

Abstract:

Consider the random graph process starting from an empty graph on n vertices, with one random edge being placed in each step. For a given graph H, at which step of the process will H appear as a subgraph?

Fast Computing Betweenness Centrality with Virtual Nodes on Large Sparse Networks

Abstract:

Betweenness centrality is an essential index for analysis of complex networks.