Past Events

Let G be a simple connected graph and A(G) be its adjacency matrix. A nonsingular graph G is said to have the reciprocal eigenvalue property if the reciprocal of each eigenvalue of G is also an eigenvalue. Furthermore, if each eigenvalue of G and its...

TBC

From a directed graph $Q$, called a quiver, one can construct what is known as a quiver variety $Y_Q$, an algebraic variety defined as a quotient of a vector space by a group defined in terms of $Q$. A mutation of a quiver is an operation that...

Bilevel optimization has been widely used in a variety of areas such as adversarial training, hyperparameter tuning, image reconstruction meta-learning, neural architecture search, and reinforcement learning. In this talk, I will present first-order...

Euler’s famous formula tells us that (with appropriate caveats), a map on the sphere with f countries (faces), e borders (edges), and v border-ends (vertices) will satisfy v-e+f=2. And more generally, for a map on a surface with g holes, v-e+f=2-2g...

To describe the cellular self-aggregation phenomenon, some strongly coupled PDEs named as Keller-Segel (KS) and Patlak-Keller-Segel (PKS) systems were proposed in 1970s. Since KS and PKS systems possess relatively simple structures but admit rich...

From a directed graph $Q$, called a quiver, one can construct what is known as a quiver variety $Y_Q$, an algebraic variety defined as a quotient of a vector space by a group defined in terms of $Q$. A mutation of a quiver is an operation that...

Bilevel optimization has been widely used in a variety of areas such as adversarial training, hyperparameter tuning, image reconstruction meta-learning, neural architecture search, and reinforcement learning. In this talk, I will present first-order...

In 1954, Tutte made a conjecture that every graph without a cut-edge has a nowhere-zero 5-flow. A parallel conjecture to this, but for signed graphs is Bouchet’s Conjecture (1983) that every signed graph without the obvious obstruction has a nowhere...

Knowledge of the behaviour of random walks on a fintiely generated group G carries a lot of information about intrinsic properties of G. The simplest and the most well-known demonstration of this principle is the Kesten's criterion of the amenability...