Life on a closed timelike curve
arXiv:2405.18640 · doi:10.1088/1361-6382/ad98df
Abstract
We study the internal dynamics of a hypothetical spaceship traveling on a close timelike curve in an axially symmetric universe. We choose the curve so that the generator of evolution in proper time is the angular momentum. Using Wigner's theorem, we prove that the energy levels internal to the spaceship must undergo spontaneous discretization. The level separation turns out to be finely tuned so that, after completing a roundtrip of the curve, all systems are back to their initial state. This implies, for example, that the memories of an observer inside the spaceship are necessarily erased by the end of the journey. More in general, if there is an increase in entropy, a Poincaré cycle will eventually reverse it by the end of the loop, forcing entropy to decrease back to its initial value. We show that such decrease in entropy is in agreement with the eigenstate thermalization hypothesis. The non-existence of time-travel paradoxes follows as a rigorous corollary of our analysis.
arXiv comment10 pages, 3 figures, published on CQG, see https://iopscience.iop.org/article/10.1088/1361-6382/ad98df
References in corpus (15)
- Chaos and Quantum Thermalization
- Thermalization and its mechanism for generic isolated quantum systems
- The approach to thermal equilibrium in quantized chaotic systems
- Closed timelike curves via post-selection: theory and experimental demonstration
- Can the Universe Create Itself?
- The Physics of 'Now'
- Formation of closed timelike curves in a composite vacuum/dust asymptotically-flat spacetime
- Simple Quantum Systems in Spacetimes with Closed Timelike Curves
- Chronology Protection in anti-de Sitter
- Causality Violation and Naked Time Machines in AdS_5
- Topological censorship and chronology protection
- Reversible dynamics with closed time-like curves and freedom of choice
- Causal paradoxes: a conflict between relativity and the arrow of time
- A time machine for free fall into the past
- Relating chronology protection and unitarity through holography