Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
PDF files require Adobe Acrobat Reader.
Title: Symmetry of random graphs
Speaker: | Jane Gao |
Affiliation: | University of Waterloo |
Zoom: | Please email Emma Watson |
Abstract:
A graph is said asymmetric if its automorphism group contains only the identity permutation. Otherwise, it is said symmetric. In this talk we will survey symmetry of Erdos-Renyi random graphs, of random regular graphs, and of random graphs with moderate degree sequences.
Title: The e-positivity of chromatic symmetric functions
Speaker: | Steph van Willigenburg |
Affiliation: | University of British Columbia |
Zoom: | Contact Karen Yeats |
Abstract:
The chromatic polynomial was generalized to the chromatic symmetric function by Stanley in his seminal 1995 paper. This function is currently experiencing a flourishing renaissance, in particular the study of the positivity of chromatic symmetric functions when expanded into the basis of elementary symmetric functions, that is, e-positivity.
Title: Nakajima quiver varietites and irreducible components of Springer fibers
Speaker: | Mee Seong |
Affiliation: | United States Military Academy and Army Research Laboratory |
Zoom: | Contact Karen Yeats |
Abstract:
Springer fibers and Nakajima quiver varieties are amongst the most important objects in geometric representation theory. While Springer fibers can be used to geometrically construct and classify irreducible representations of Weyl groups, Nakajima quiver varieties play a key role in the geometric representation theory of Kac--Moody Lie algebras.
Zoom (for information email emma.watson@uwaterloo.ca)
Title: Permanent Hardness from Linear Optics
Speaker: | Daniel Grier |
Affiliation: | University of Waterloo |
Location: | Online (Zoom) |
Abstract:
One of the great accomplishments in complexity theory was Valiant's 1979 proof that the permanent of a matrix is #P-hard to compute. Subsequent work simplified Valiant's ideas and even began to recast them as problems in quantum computing. In 2011, this culminated in a striking proof by Aaronson, based solely on quantum linear optics, of the #P-hardness of the permanent.
Title: Combinatorial masters in QED
Speaker: | Oliver Schnetz |
Affiliation: | Friedrich-Alexander Universität Erlangen |
Zoom: | Contact Karen Yeats |
Abstract:
Calculations in perturbative QED (and also in QCD) use a reduction from Feynman integrals to `master integrals'. In general, the reduction to master integrals is performed by excessive use of computer power.
Zoom (for information email emma.watson@uwaterloo.ca)
Title: Hardness of set-partitioning formulation for the vehicle routing problem with stochastic demands
Speaker: | Ricardo Fukasawa |
Affiliation: | University of Waterloo |
Location: | Online (Zoom) |
Abstract:
The vehicle routing problem considers the cheapest way to serve a set of customers using a fixed set of vehicles. When a vehicle serves a customer, it picks up its demand which is given as an input, and the total demand picked up cannot exceed the vehicle’s capacity. This classical combinatorial optimization problem combines aspects of routing (like a traveling salesman problem) and packing (like a knapsack problem).
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
PDF files require Adobe Acrobat Reader.
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Office of Indigenous Relations.