Cubic inflation, mirror graphs, regular maps, and partial cubes

Partial cubes are, by definition, isometric subgraphs of hypercubes. Cubic inflation is an operation that transforms a 2-cell embedded graph G into a cubic graph embedded in the same surface; its result can be described as the dual of the barycentric subdivision of G. New concepts of mirror and pre-mirror graphs are also introduced. They give rise to a characterization of Platonic graphs (i) as pre-mirror graphs and (ii) as planar graphs of minimum degree at least three whose cubic inflation is a mirror graph. Using cubic inflation we find five new prime cubic partial cubes.