Vortex Nerves and their Proximities. Nerve Betti Numbers and Descriptive Proximity

Abstract

This article introduces vortex nerve complexes in CW (Closure finite Weak) topological spaces, which first appeared in works by P. Alexandroff, H. Hopf and J.H.C. Whitehead during the 1930s. A vortex nerve is a CW complex containing one or more intersecting path-connected cycles. Each vortex nerve has its own distinctive shape. Both vortex nerve shapes (bounded planar surfaces with nonempty interior) and holes (bounded planar surfaces with empty interior that live inside and define shapes) have boundaries that are path-connected cycles. In the context of CW complexes, the usual Betti numbers $\mathcal{B}_0$ (cell count), $\mathcal{B}_1$ (cycle count) and $\mathcal{B}_2$ (hole count) provide a basis for the introduction of several new Betti numbers, namely, vortex $\mathcal{B}_{vtex}$, vortex nerve $\mathcal{B}_{vNrv}$ and shape $\mathcal{B}_{sh}$ introduced in this paper. In addition, results are given for CW complexes equipped with a descriptive proximity as well as for the homotopy types of vortex nerves and the complexes and cycles contained in the nerves.