Mathematics

Relations between Spectral Sequences

Liz Tatum (Illinois Math)

Abstract: Consider a ring spectrum E and a spectrum X. The E-based Adams Spectral Sequence is a tool for approximating the homotopy groups $\pi_{*}X$. Depending on the choice of ring spectrum E, the Adams spectral sequence might be easier to compute, but might give a weaker approximation to $\pi_{*}X$. One could ask “If A, B are two different ring spectra, what can an A-based Adams spectral sequence tells us about a B-based Adams spectral sequence”? In the paper “On Relations Between Adams Spectral Sequences, With an Application to the Stable Homotopy of a Moore Space”, Miller proves a theorem addressing this question. In this talk, I’ll introduce some of the tools Miller uses to formulate and prove this theorem, and outline the previously mentioned application.

Analytic torsions associated with the Rumin complex on contact spheres

Akira Kitaoka (University of Tokyo)

Abstract: The Rumin complex, which is defined on contact manifolds, is a resolution of the constant sheaf of $\mathbb{R}$ given by a subquotient of the de Rham complex. In this talk, we explicitly write down all eigenvalues of the Rumin Laplacian on the standard contact spheres, and express the analytic torsion functions associated with the Rumin complex in terms of the Riemann zeta function. In particular, we find that the functions vanish at the origin and determine the analytic torsions.

Linear Analysis on Singular Spaces

Hadrian Quan

Abstract: As an undergraduate, one may be introduced to the 3 classic linear differential equations: Laplace’s equation, the heat equation, and the wave equation. Simply trying to solve these equations in different coordinate systems leads to a zoo of different solutions; such variation reflects the strong connection between the geometry of a space, and the behavior of solutions to these PDE on that space. Passing from Euclidean space to more general manifolds, these three equations can be studied whenever our manifold is equipped with the geometric structure of a Riemannian metric. In this talk I will highlight a few of the many surprising theorems exhibiting this connection between the geometry and topology of a manifold and the behavior of solutions to the Laplace, heat, and wave equation. Time permitting, I’ll highlight recent joint work with Pierre Albin of some new phenomena on certain singular spaces.