Past Events

In the bounded retrieval model, the adversary has malware on the message sender’s computer that can leak a certain amount of information (e.g., 10 percent of the size of the hard drive). In this setting, Bellare, Kane and Rogaway gave an efficient symmetric encryption scheme. Their scheme uses a…

Abstract: I will continue discussing the formalism of flow categories,
and in particular discuss the changes required to account for the fact
that there usually is no well-defined action functional, which
requires one to work with Novikov ring/field coefficients.

Abstract: In this talk, by using the trace formula method, I will prove a multiplicity formula of K-types for all representations of real reductive groups in terms of the Harish-Chandra character. 

The angle rank of an abelian variety over a finite field (or a CM abelian variety over C) quantifies the extent to which the Tate conjecture (or the Hodge conjecture) holds "for trivial reasons"; cases where this does not happen tend to be rare in practice. Picking up a thread from some old (…

Fix a forbidden subgraph H and a constant δ. Suppose G is an H-free graph with minimum degree at least δ|V(G)|. We are interested in the following question: for which δ do all such G have a shared finite H-free homomorphic image? For r > 1, we construct a family of dense …

A 7D minimal and locally-stable hypersurface will in general have a discrete singular set, provided it has no singularities modeled on a union of half-planes.  We show in this talk that the geometry/topology/singular set of these surfaces has uniform control, in the following sense: if $M_i…

The basic question is the evolution of the level sets of the solutions to equations of the Fisher-KPP type, in which the diffusion is given by an integral operator. Mathematically, they will organise themselves into an invasion front that is asymptotically…

I will discuss joint work with Braeden Reinoso and Ethan Farber on showing that the pseudo-Anosov representative of any genus-two, hyperbolic, fibered knot in the 3-sphere with nonzero fractional Dehn twist coefficient has an interior fixed point. Combined with work of Baldwin-Hu-Sivek where…

Very sparse random graphs are known to typically be singular (i.e., have singular adjacency matrix), due to the presence of "low-degree dependencies" such as isolated vertices and pairs of degree-1 vertices with the same neighborhood. We prove that these kinds of dependencies are in some sense…

Abstract: Cohen, Jones, and Segal formalised the structure of the
moduli spaces that appear in Floer theory as a "flow category." I will
define this notion, and then explain how to associated to a flow
category (of oriented manifold) a collection of bordism groups. These
bordism…