Previous Conferences & Workshops

Given the edge density $\rho$ of an undirected graph, what is the minimal possible density $g(\rho)$ of triangles in this graph? This is the quantitative version of the classical Turan theorem (41) that in the asymptotical form can be re-stated as...

Let $F$ be a family of graphs. A graph $H$ is *$F$-universal* if every $G\in F$ is isomorphic to a subgraph of $H$. Besides being of theoretical interest, universal graphs have applications in chip design and network simulation. For any two positive...

We consider maps between smooth projective curves and some arithmetic and geometric properties of such maps. In particular, we will discuss the case of maps from the generic Riemann surface of genus g -- a problem first seriously looked at by...

I will present results on the critical behavior of directed polymer models interacting with a defect line, in presence of quenched disorder. These models show a localization-delocalization phase transition. Our main result is that the transition in...

Let $G$ be a simple $G(\mathbf Q)$-group of $G(\mathbf Q)$-rank at least 2. In 1987 T. N. Venkataramana showed that if $\Gamma \subset G(\mathbf Z)$ is an infinite subgroup whose commensurator is a subgroup of finite index in $G(\mathbf Z)$, then $...

Given the edge density $\rho$ of an undirected graph, what is the minimal possible density $g(\rho)$ of triangles in this graph? This is the quantitative version of the classical Turan theorem (41) that in the asymptotical form can be re-stated as...

We'll begin with the following theorem, which proves a conjecture of S\'ark\"ozy, Selkow and Szemer\'edi, and try to use it as an excuse to talk about other things (perhaps including Br\'egman's Theorem, entropy, the ``incremental random method,"...