Multi-Dimensional Cohomological Phenomena in the Multiparametric Models of Random Simplicial Complexes

Abstract: In the past two decades, extensive research has been conducted on the (co)homology of various models of random simplicial complexes. So far, it has always been examined merely as a list of groups. This paper expands upon this by describing both the ring structure and the Steenrod-algebra structure of the cohomology of the multiparametric models. For the lower model, we prove that the ring structure is always a.a.s trivial, while, for certain parameters, the Steenrod-algebra a.a.s acts non-trivially. This reveals that complex multi-dimensional topological structures appear as subcomplexes of this model. In contrast, we improve upon a result of Farber and Nowik, and assert that the cohomology of the upper multiparametric model is a.a.s concentrated in a single dimension.