Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reversible dynamics with closed time-like curves and freedom of choice   The theory of general relativity predicts the existence of closed time-like
curves (CTCs), which theoretically would allow an observer to travel back in
time and interact with their past self. This raises the question of whether
this could create a grandfather paradox, in which the observer interacts in
such a way to prevent their own time travel. Previous research has proposed a
framework for deterministic, reversible, dynamics compatible with non-trivial
time travel, where observers in distinct regions of spacetime can perform
arbitrary local operations with no contradiction arising. However, only
scenarios with up to three regions have been fully characterised, revealing
only one type of process where the observers can verify to both be in the past
and future of each other. Here we extend this characterisation to an arbitrary
number of regions and find that there exist several inequivalent processes that
can only arise due to non-trivial time travel. This supports the view that
complex dynamics is possible in the presence of CTCs, compatible with free
choice of local operations and free of inconsistencies.

28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph