Jeffery Mensah

In this post, we discuss an invariant of a complex representation of a finite group, and show how this yields a connection between irreducible real and complex representations...

This post builds off of Roger Penrose's article On the Cohomology of Impossible Figures, in which he shows a remarkable connection betweeen impossible drawings, such as the Penrose triangle, and nontrivial cohomology groups...

The snake lemma is a fundamental tool of homological algebra which is primarily used in the construction of the homology long exact sequence. It's proof, like many others in homological algebra, is an exercise in diagram chasing...