Computers with Closed Timelike Curves Can Solve Hard Problems Efficiently

  title={Computers with Closed Timelike Curves Can Solve Hard Problems Efficiently},
  author={Todd A. Brun},
  journal={Foundations of Physics Letters},
  • T. Brun
  • Published 18 September 2002
  • Computer Science
  • Foundations of Physics Letters
A computer which has access to a closed timelike curve, and can thereby send the results of calculations into its own past, can exploit this to solve difficult computational problems efficiently. I give a specific demonstration of this for the problem of factoring large numbers and argue that a similar approach can solve NP-complete and PSPACE-complete problems. I discuss the potential impact of quantum effects on this result. 
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