Realization problems of graphs as Reeb graphs of Morse functions with prescribed preimages

Abstract

The present paper is on a new result on so-called realization problems of graphs as Reeb graphs of Morse functions with prescribed preimages. The Reeb graph of a smooth function is a graph obtained by identifying two points in the manifold of the domain if and only if they are in a same connected component of some preimage. In considerable cases such as cases where functions are Morse-Bott functions on closed manifolds we obtain such graphs. Reeb graphs represent the manifolds of the domains compactly. They are not only fundamental tools in geometry using differentiable functions and maps as fundamental tools, but also in applications of mathematics such as visualizations. Realization problems are also fundamental and important. Construction of functions with prescribed preimages was considered first by the author essentially and before the present study, the author has obtained a result.