Rotating Boson Stars and Q-Balls
  We consider axially symmetric, rotating boson stars. Their flat space limits represent spinning Q-balls. We discuss their properties and determine their domain of existence. Q-balls and boson stars are stationary solutions and exist only in a limited frequency range. The coupling to gravity gives rise to a spiral-like frequency dependence of the boson stars. We address the flat space limit and the limit of strong gravitational coupling. For comparison we also determine the properties of spherically symmetric Q-balls and boson stars. 
Burkhard Kleihaus (1), Jutta Kunz (1), Meike List (1 and 2) (1)   (Universit\"at Oldenburg) (2) (ZARM, Universit\"at Bremen)