Spheres as Frobenius objects

Abstract

Following the pattern of the Frobenius structure usually assigned to the 1-dimensional sphere, we investigate the Frobenius structures of spheres in all other dimensions. Starting from dimension d = 1, all the spheres are commutative Frobenius objects in categories whose arrows are (d + 1)-dimensional cobordisms. With respect to the language of Frobenius objects, there is no distinction between these spheres–they are all free of additional equations formulated in this language. The corresponding structure makes out of the 0-dimensional sphere not a commutative but a symmetric Frobenius object. This sphere is mapped to a matrix Frobenius algebra by a 1-dimensional topological quantum field theory, which corresponds to the representation of a class of diagrammatic algebras given by Richard Brauer.