Department of Mathematics

Co-organizers:

Vladimir Retakh (retakh {at} math [dot] rutgers [dot] edu)

Anthony Zaleski (az202 {at} math [dot] rutgers [dot] edu)

Symplectic geometry has recently emerged as a key tool in the study of low-dimensional topology. One approach, championed by Arnol'd, is to examine the topology of a smooth manifold through the symplectic geometry of its cotangent bundle, building on the familiar concept of phase space from classical mechanics. I'll focus on one particular application of this approach that yields strong invariants of knots. I'll discuss a mysterious connection between these knot invariants and string theory, as well as a recent result (joint with Tobias Ekholm and Vivek Shende) that the invariants completely determine the underlying knot.

Thomson's problem, which goes back to 1904, asks how N points will arrange themselves on the sphere so as to minimize their electrostatic potential. A more general problem asks what happens for other power law potentials. In spite of quite a bit of experimental evidence accumulated over the past century, and some spectacular results for values of N associated with highly symmetric polyhedra, there have been few rigorous results for the modest case N=5. In my talk I will explain my recent proof that, for N=5, the triangular bi-pyramid is the minimizer with respect to all power laws up to a constant S=15.04808..., and then the minimizer changes to a pyramid with square base. My talk will have some nice computer animations.

The asymmetric simple exclusion process (ASEP) is a Markov chain describing particles hopping on a 1-dimensional finite lattice. Particles can enter and exit the lattice at the left and right boundaries, and particles can hop left and right in the lattice, subject to the condition that there can be at most one particle per site. The ASEP has been cited as a model for traffic flow, protein synthesis, the nuclear pore complex, etc. In my talk I will discuss joint work with Corteel and with Corteel-Mandelshtam, in which we describe the stationary distribution of the ASEP and the 2-species ASEP using staircase tableaux and rhombic tilings. I will also discuss the link between these models and Askey-Wilson polynomials and Macdonald-Koornwinder polynomials.

Strominger, Yau, and Zaslow proposed a geometric explanation for mirror symmetry via a dualization procedure relating symplectic manifolds equipped with Lagrangian torus fibration with complex manifolds equipped with totally real torus fibrations. By considering the family of symplectic manifolds obtained by rescaling the symplectic form, one obtains a degenerating family of complex manifolds, which is expected to be the mirror.

Because of convergence problems with Floer theoretic constructions, it is difficult to make this procedure completely rigorous. Kontsevich and Soibelman thus proposed to consider the mirror as a rigid analytic space, defined over the field C((t)), equipped with the non-archimedean t-adic valuation, or more generally over the Novikov field. This is natural because the Floer theory of a symplectic manifold is defined over the Novikov field.

After explaining this background, I will give some indication of the tools that enter in the proof of homological mirror symmetry in the simplest class of examples which arise from these considerations, namely Lagrangian torus fibrations without singularities.

This page is maintained by Anthony Zaleski.