It is known that any strict tensor category （C, I） can determine a strict braided tensor category Z （ C）, the centre of C. W......

In this paper, it is proved that the global dimension of a Yetter-Drinfel’d Hopf algebra coincides with the projective ......

This paper introduces the concept of’ symmetric centres’ of braided monoidal categories. Let H be a Hopf algebra with ......