Editing Closed timelike curve (section)

== Cauchy horizon ==
The [[chronology violating set]] is the set of points through which CTCs pass. The boundary of this set is the [[Cauchy horizon]]. The Cauchy horizon is generated by closed null geodesics.<ref>{{Cite journal |last=Thorne |first=Kip |date=1992 |title=Closed timelike curves |url=https://s3.cern.ch/inspire-prod-files-9/9e243ddb6420681ac2362781c9754c04 |journal=General Relativity and Gravitation |pages=297}}</ref> Associated with each closed null geodesic is a redshift factor describing the rescaling of the rate of change of the affine parameter around a loop. Because of this redshift factor, the affine parameter terminates at a finite value after infinitely many revolutions because the geometric series converges.