Representations of copointed Hopf algebras arising from the tetrahedron rack

Abstract

We study the copointed Hopf algebras attached to the Nichols algebra of the affine rack Aff(F4,w), also known as tetrahedron rack, and the 2-cocycle −1. We investigate the so-called Verma modules and classify all the simple modules. We conclude that these algebras are of wild representation type and not quasitriangular, also we analyze when these are spherical.