Unitarity in the Presence of Closed Timelike Curves

@misc{ pirsa_PIRSA:05100008,
  doi = {10.48660/05100008},
  url = {https://pirsa.org/05100008},
  author = {Cornalba, Lorenzo},
  keywords = {Cosmology},
  language = {en},
  title = {Unitarity in the Presence of Closed Timelike Curves},
  publisher = {Perimeter Institute},
  year = {2005},
  month = {oct},
  note = {PIRSA:05100008 see, \url{https://pirsa.org}}
}