Comment on "Information flow of quantum states interacting with closed   timelike curves"
  We show that recent results on the interaction of causality-respecting particles with particles on closed timelike curves derived in [Phys. Rev. A 82, 062330 (2010)] depend on ambiguous assumption about the form of the state which is inputted into the proposed equivalent circuit. Choosing different form of this state leads to opposite conclusion on the power of closed timelike curves. 
Waldemar Klobus, Andrzej Grudka, Antoni Wojcik
quant-ph gr-qc