An axiomatic characterization of Steenrod's cup- products
arXiv:1810.06505
Abstract
We show that any natural construction of cup- products on the normalized cochains of simplicial sets, parameterized by the minimal free resolution of the trivial -module, is isomorphic---not just homotopic---to Steenrod's original construction if it is non-zero, irreducible, and free. We show that these three conditions are independent, and use them to prove that all cup- constructions in the literature represent the same isomorphism class.
Add independency of axioms and semi-simplicial naturality