Steenrod algebra

Steenrod algebra is a fundamental concept in algebraic topology, specifically in the study of cohomology theories. It arises from the work of the mathematician Norman Steenrod in the mid-20th century and is primarily concerned with the operations on the cohomology groups of topological spaces. The core idea behind Steenrod algebra is the introduction of certain cohomology operations, known as Steenrod squares, which act on the cohomology groups of topological spaces.