Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
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Monday, December 13, 2021 11:30 AM EST
Title: A New Graph Polynomial from the Chromatic Symmetric Function
| Speaker: | Logan Crew |
| Affiliation: | University of Waterloo |
| Zoom: | Contact Soffia Arnadottir |
Abstract:
The chromatic symmetric function X_G of a graph generalizes the chromatic polynomial by distinguishing proper n-colourings by how many times each colour is used. Furthermore, many other natural graph polynomials also arise from specializations of X_G;
Monday, December 6, 2021 11:30 AM EST
Title: On the Laplacian spectra of token graphs
| Speaker: | Cristina Dalfó |
| Affiliation: | Universitat de Lleida |
| Zoom: | Contact Soffia Arnadottir |
Abstract:
We study the Laplacian spectrum of token graphs, also called symmetric powers of graphs. The k-token graph F_k(G)of a graph G is the graph whose vertices are the k-subsets of vertices from G, two of which being adjacent whenever their symmetric difference is a pair of adjacent vertices in G. In this talk, we give a relationship between the Laplacian spectra of any two token graphs of a given graph.
Friday, December 3, 2021 3:30 PM EST
Title: Warped Proximal Iterations for Multivariate Convex Minimization in Hilbert Spaces
| Speaker: | Minh Bui |
| Affiliation: | University of Waterloo |
| Zoom: | Please email Emma Watson |
Abstract:
We propose a multivariate convex minimization model which involves a mix of nonsmooth and smooth functions, as well as linear mixtures of the variables. This formulation captures a wide range of concrete scenarios in the literature. A limitation of existing methods is that they do not achieve full splitting of our problem in the sense that each function and linear operator is activated separately. To circumvent this issue, we propose a novel approach, called warped proximal iterations, for solving this problem.