Closed Timelike Curves in Relativistic Computation
  In this paper, we investigate the possibility of using closed timelike curves (CTCs) in relativistic hypercomputation. We introduce a wormhole based hypercomputation scenario which is free from the common worries, such as the blueshift problem. We also discuss the physical reasonability of our scenario, and why we cannot simply ignore the possibility of the existence of spacetimes containing CTCs. 
Hajnal Andr\'eka, Istv\'an N\'emeti and Gergely Sz\'ekely
gr-qc math-ph math.LO math.MP