Treating Time Travel Quantum Mechanically

@article{Allen2014TreatingTT,
  title={Treating Time Travel Quantum Mechanically},
  author={John-Mark Allen},
  journal={Physical Review A},
  year={2014},
  volume={90},
  pages={042107}
}
The fact that closed timelike curves (CTCs) are permitted by general relativity raises the question as to how quantum systems behave when time travel to the past occurs. Research into answering this question by utilising the quantum circuit formalism has given rise to two theories: Deutschian-CTCs (D-CTCs) and "postselected" CTCs (P-CTCs). In this paper the quantum circuit approach is thoroughly reviewed, and the strengths and shortcomings of D-CTCs and P-CTCs are presented in view of their non… 

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