COBOUNDARY EXPANDERS
Dominic Dotterrer, Matthew Kahle · Journal of Topology and Analysis · 2012
We describe a higher-dimensional generalization of edge expansion from graphs to simplicial complexes, which we discuss as a type of co-isoperimetric inequality. The main point is to observe that sufficiently dense random simplicial complexes have this expander-like property with high probability, a higher-dimensional analogue of the fact that random graphs are expanders.