"Semiprime smash products - a survey on a problem by Cohen & Fishman".

"Motivated by results from the theory of group actions and of the theory of group graded rings, Cohen and Fishman asked in 1986 whether the smash product of a semisimple Hopf algebra and a semiprime algebra is semiprime again. We will give a survey on past results of this problems and on recent developments by Linchenko and Montgomery which give an affirmative answer in case A satisfies a polynomial identity."