Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
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Friday, March 16, 2018 3:30 PM EDT
Title: A George Szekeres formula for restricted partitions
| Speaker: | Bruce Richmond |
| Affiliation: | University of Waterloo |
| Room: | MC 5501 |
Abstract:
We give asymptotic formulas for the number of integer partitions of n with at most j parts and having largest part at most r, say A(n,j,r). We do this also for the number of partitions of n with largest part equal to r and having exactly j parts, say C(n,j,r).
Thursday, March 15, 2018 1:30 PM EDT
Title: Quantum State Transfer
| Speaker: | Christopher van Bommel |
| Affilliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
Many quantum algorithms may be modeled as a quantum process occurring on a graph. We interpret quantum channels implemented by spin chains as wires for transmission of states.
Wednesday, March 14, 2018 4:00 PM EDT
Title: Data-driven Inverse Optimization with Imperfect Information
| Speaker: | Stefan Sremac |
| Affilliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
We continue our reading group with a paper by Kuhn et al with the same title as above.
Tuesday, March 13, 2018 4:30 PM EDT
Title: What's an amplituhedron?
| Speaker: | Cameron Marcott |
| Affilliation: | University of Waterloo |
| Room: | MC 5501 |
Abstract:
I'll introduce the amplituhedron, focusing on why the suffix "hedron" is justified.
Monday, March 12, 2018 1:30 PM EDT
Title: LWE Part 1: The problem, the cryptosystem and its relationship to lattice Problems
| Speaker: | Luiz Ruiz |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
In this talk we will give an overview of the Learning With Errors problem,
Friday, March 9, 2018 3:30 PM EST
Title: Chromatic Symmetric Functions and H-Free Graphs
| Speaker: | Angèle Hamel |
| Affiliation: | Wilfrid Laurier University |
| Room: | MC 2038 (not 5501) |
Abstract:
Chromatic symmetric functions are defined in terms of colourings of particular graphs. Some key conjectures in this area concern whether chromatic symmetric functions of claw-free graphs can be written in terms of other symmetric functions with positive coefficients.
Thursday, March 8, 2018 3:30 PM EST
Title: Claws, ω and χ: induced binary submatroids
| Speaker: | Peter Nelson |
| Affilliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
I will discuss the interplay between clique number, chromatic number, and excluding induced submatroids in the setting of binary matroids.
Thursday, March 8, 2018 1:30 PM EST
Title: Unitary Groups, II
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
Actually the title should be 2 Unitary groups - I will discuss the 2-dimensional unitary groups.
Monday, March 5, 2018 3:30 PM EST
Title: Traveling Salesman Problems
| Speaker: | William (Bill) Cook |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
We discuss open research questions, both theoretical and computational, surrounding the traveling salesman problem.
Thursday, March 1, 2018 3:30 PM EST
Title: Counting matroids
| Speaker: | Jorn van der Pol |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
We discuss several recent results concerning matroid enumeration and typical properties of matroids, emphasizing the central role that sparse paving matroids play in these results.
Thursday, March 1, 2018 1:30 PM EST
Title: Unitary Groups
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
Unitary groups play an important role in physics and in finite geometry. This talk, the first of two, will provide an introduction to the topic focusing on the case where the underlying field is the complex numbers.
Monday, February 26, 2018 10:30 AM EST
Title: Random Networks: Enumeration, Generation, and Universality
| Speaker: | Pu (Jane) Gao |
| Affilliation: | Monash University |
| Room: | DC 1304 |
Abstract:
Large networks appear in almost all branches of the sciences and in everyday life, and they are often modeled by random graphs. Among the various random graph models, random graphs with specified degrees are particularly important in modelling and analyzing real-world networks.
Friday, February 16, 2018 3:30 PM EST
Title: Tangent Lines and the equation 28 = 7 × 4
| Speaker: | Yoav Len |
| Affiliation: | University of Waterloo |
| Room: | MC 5501 |
Abstract:
I will discuss combinatorial aspects of tangent lines to curves and planar graphs. In algebraic geometry, every smooth plane curve has finitely many lines that are tangent to it at two separate points.
Thursday, February 15, 2018 3:30 PM EST
Title: An introduction to gammoids
| Speaker: | Rutger Campbell |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
A gammoid is a matroid that is defined via vertex connectivity in a graph.
Thursday, February 15, 2018 1:30 PM EST
Title: Mixing in Discrete-Time Quantum Walks
| Speaker: | Harmony Zhan |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
Discrete-time quantum walks are building blocks for quantum algorithms. There are some parameters of a quantum walk that affect the performance of a quantum algorithm, such as the (time-averaged) limiting distribution and the mixing time.
Wednesday, February 14, 2018 4:00 PM EST
Title: Comprehensive robust counterparts of uncertain problems
| Speaker: | Sina Rezazadeh |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
We continue our study of Robust Optimization by discussing the paper by Ben-Tal, Boyd and Nemirovski, "Extending scope of robust optimization: comprehensive robust counterparts of uncertain problems."
Friday, February 9, 2018 3:30 PM EST
Title: Post-Quantum Group-based Cryptography
| Speaker: | Delaram Kahrobaei |
| Affiliation: | New York University |
| Room: | MC 5501 |
Abstract:
The National Security Agency (NSA) in August 2015 announced plans to transition to post-quantum algorithms
Thursday, February 8, 2018 3:30 PM EST
Title: An introduction to vertex minors
| Speaker: | Jim Geelen |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
This introductory lecture on vertex minors of graphs will highlight the similarities and differences with minors of graphs. We will also discuss the main conjectures relating to vertex minors.
Thursday, February 8, 2018 1:30 PM EST
Title: Constructing Graphs Pseudo-Similar Vertices
| Speaker: | Cathy Wang |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
Let G be a graph. Let a and b be vertices in G, then a and b are pseudo-similar if G\a is isomorphic to G\b, but there's no automorphism of G that maps a onto b.
Wednesday, February 7, 2018 4:00 PM EST
Title: Robust Convex Optimization
| Speaker: | Nargiz Kalantarova |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
We continue our study of convex optimization problems with uncertain data by discussing the paper by Ben-Tal and Nemirovski, 'Robust Convex Optimization'.
Tuesday, February 6, 2018 4:30 PM EST
Title: An Introduction to Quantum Graphs, Chromatic Numbers and Lovász Inequalties
| Speaker: | Arthur Mehta |
| Affiliation: | Pure Math - University of Waterloo |
| Room: | MC 5501 |
Abstract:
Quantum graph theory, also known as non-commutative graph theory, is an operator system generalization of graph theory. Quantum graphs were first used to extend the notion of one-shot-zero-error capacity of a "Noisy Channel" to "Quantum Channels".
Monday, February 5, 2018 9:30 PM EST
Title: Algorithms and complexity for quantum advantage
| Speaker: | David Gosset |
| Affiliation: | IBM - T.J. Watson Research Center |
| Room: | QNC 0101 |
Abstract:
There is strong evidence that a sufficiently large fault-tolerant quantum computer would solve certain computational problems exponentially faster than any classical computer. How can quantum algorithms and complexity theory help guide the way forward in our current era of small and noisy quantum computers?
Monday, February 5, 2018 1:00 PM EST
Title: ALBANIS: A brief overview of Lattice-Based NIST Submissions
| Speaker: | Luis Ruiz |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
Now that the NIST competition is in the first round of the review process, it is our turn to take a look at the submissions (at least, briefly).
Friday, February 2, 2018 9:30 AM EST
Title: Polynomial systems: Graphical structure, Geometry, and Applications
| Speaker: | Diego Cifuentes |
| Affiliation: | MIT |
| Room: | MC 5501 |
Abstract:
Various problems in areas such as robotics, power systems, computer vision, cryptography, and chemical reaction networks, can be modeled by systems of polynomial equations, and in many cases the resulting systems have a simple sparsity structure.
Thursday, February 1, 2018 1:30 PM EST
Title: On Pretty Good State Transfer, Entanglement, and Spin Chains
| Speaker: | Christopher van Bommel |
| Affiliation: | University of Waterloo |
| Room: | MC 6486 |
Abstract:
We discuss the Vieira and Rigolin paper “Almost perfect transport of an entangled two-qubit state through a spin chain”,