Arthur and Merlin in a quantum world

Arthur does not have a lot of time to spend performing difficult computations. He´s recently obtained a quantum computer, but often it seems not to help - he only has a few quantum algorithms, and Merlin maintains that there aren´t any other interesting ones, so Merlin is forced to convince the untrusting Arthur of the truth of various facts. However, Arthur and Merlin have a new resource at their disposal: quantum information. Some relationships among complexity classes defined by quantum Arthur-Merlin games and other commonly studied complexity classes are known, but many open questions remain. In this paper, I discuss quantum Arthur-Merlin games in detail, with an emphasis on open problems