Fusion category explained

k

is algebraically closed, then the latter is equivalent to

Hom(1,1)\congk

by Schur's lemma.

Examples

G

of cardinality

n

over a field

K

is a fusion category if and only if

n

and the characteristic of

K

are coprime. This is because of the condition of semisimplicity which needs to be checked by the Maschke's theorem.

Reconstruction

Under Tannaka–Krein duality, every fusion category arises as the representations of a weak Hopf algebra.

References

Book: Etingof. Pavel. Nikshych. Dmitri. Ostrik. Viktor. 2005. Tensor Categories. 0885-4653.