Intersection numbers from the antisymmetric Gaussian matrix model

Open intersection numbers, matrix models and MKP hierarchy

In this paper we conjecture that the generating function of the intersection numbers on the moduli spaces of Riemann surfaces with boundary, constructed recently by R. Pandharipande, J. Solomon and R. Tessler and extended by A. Buryak, is a taufunction of the KP integrable hierarchy. Moreover, it is given by a simple modification of the Kontsevich matrix integral so that the generating function...

An Antisymmetric Effective Hall Matrix

A periodic composite of four isotropic phases with an almost antisymmetric effective Hall matrix is constructed. This is done through the use of a microstructure, with high contrast conductivity, which acts to twist the direction of the induced Hall field. For an applied current along the y3 axis and a magnetic field h in the y1-y2 plane the Hall field will be essentially parallel, rather than ...

Virtual Intersection Numbers

Intersection homology Betti numbers

A generalization of the formula of Fine and Rao for the ranks of the intersection homology groups of a complex algebraic variety is given. The proof uses geometric properties of intersection homology and mixed Hodge theory. The middle-perversity intersection homology with integral coefficients of a compact complex n-dimensional algebraic variety X with isolated singularities is well known to be...

On Kelley’s Intersection Numbers

We introduce a notion of weak intersection number of a collection of sets, modifying the notion of intersection number due to J.L. Kelley, and obtain an analogue of Kelley’s characterization of Boolean algebras which support a finitely additive strictly positive measure. We also consider graph-theoretic reformulations of the notions of intersection number and weak intersection number. Kelley [4...