Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
PDF files require Adobe Acrobat Reader.
Thursday, April 25, 2019 4:00 PM EDT
Title: Recovery of a mixture of Gaussians by sum-of-norms clustering
| Speaker: | Tao Jiang |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
Sum-of-norms clustering is a method for assigning n points in Rd to K clusters, 1 ≤ K ≤ n, using convex optimization.
Thursday, April 18, 2019 4:00 PM EDT
Title: Graph Sparsification by Effective Resistances
| Speaker: | Akshay Ramachandran |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
We will discuss an application of the matrix concentration inequalities of Tropp to spectral sparsification of graphs.
Thursday, April 11, 2019 4:00 PM EDT
Title: Optimal detection of sparse principal components in high dimension
| Speaker: | Steve Vavasis |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
I will present the paper with this title by Berthet and Rigollet (Ann. Stat., 41 (2013) 1780-1815, https://projecteuclid.org/download/pdfview_1/euclid.aos/1378386239).
Thursday, April 11, 2019 1:30 PM EDT
Title: Erdös-Rényi Graphs
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
These might not be the Erdös-Rényi graphs you first thought of. Let V be a 3-dimensional vector space over a field of odd order q.
Friday, April 5, 2019 3:30 PM EDT
Title: Online Competitive Algorithms for Resource Allocation
| Speaker: | Maryam Fazel |
| Affiliation: | University of Washington |
| Room: | MC 5501 |
Abstract:
In online optimization with budgets, the data in the optimization problem is revealed over time. At each step a decision variable needs to be set without knowing the future inputs, while there is a budget constraint that couples the decisions across time.
Thursday, April 4, 2019 4:00 PM EDT
Title: High dimensional probability: Estimation in high dimensions
| Speaker: | Sina Baghal |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
In this talk, we discuss high dimensional estimation problems. The aim is to estimate some point x in a given ambient bounded space K using a small number of independent random observations.
Thursday, April 4, 2019 1:30 PM EDT
Title: The Perron-Frobenius Theorem
| Speaker: | Soffia Arnadottir |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
The Perron-Frobenius Theorem is an extremely important result on eigenvalues and eigenvectors of non-negative matrices.
Wednesday, April 3, 2019 4:30 PM EDT
Title: A proof of the Hell-Nešetřil Dichotomy via Siggers Polymorphisms
| Speaker: | Ben Moore |
| Affiliation: | University of Waterloo |
| Room: | MC 4020 |
Abstract:
In 2017, the constraint satisfaction dichotomy was proven via techniques from universal algebra. If we restrict this theorem to graphs, we get the Hell-Nešetřil Dichotomy, which is a statement about colouring graphs.
Tuesday, April 2, 2019 11:30 AM EDT
Title: IETF encryption standards post-TLS 1.3
| Speaker: | Nick Sullivan |
| Affiliation: | Cloudflare |
| Room: | MC 5501 |
Abstract:
TLS is one of the most important security protocols online. It’s most famously used in web browsing, providing the S in HTTPS.