The US pop princesses are both short-listed in four categories - best pop act, best song, best female act and best video. Completing the nominations for Lady Gaga is best live act and for Katy Perry "best world stage performance." Elsewhere, in the nominations list, rapper Eminem has four nominations including best song, best male act, best hip hop and best video for his Rihanna collaboration "Love the Way You Lie." British stadium rockers Muse, along with Thirty Seconds to Mars, Linkin Park and Kings of Leon, find themselves up against "Prince of Darkness" Ozzy Osbourne in the best rock category. Pop phenomenon Justin Bieber, Ke$ha, B.o.B, Plan B and Jason Derulo are nominated for best new act.