Time-travelling billiard-ball clocks: a quantum model
- URL: http://arxiv.org/abs/2007.12677v3
- Date: Wed, 19 May 2021 02:01:57 GMT
- Title: Time-travelling billiard-ball clocks: a quantum model
- Authors: Lachlan G. Bishop, Fabio Costa and Timothy C. Ralph
- Abstract summary: General relativity predicts the existence of closed timelike curves (CTCs)
A consequence of CTCs is the failure of determinism, even for classical systems.
We introduce a new quantum formulation of a classic example, where a billiard ball can travel along two possible trajectories.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: General relativity predicts the existence of closed timelike curves (CTCs),
along which an object could travel to its own past. A consequence of CTCs is
the failure of determinism, even for classical systems: one initial condition
can result in multiple evolutions. Here we introduce a new quantum formulation
of a classic example, where a billiard ball can travel along two possible
trajectories: one unperturbed and one, along a CTC, where it collides with its
past self. Our model includes a vacuum state, allowing the ball to be present
or absent on each trajectory, and a clock, which provides an operational way to
distinguish the trajectories. We apply the two foremost quantum theories of
CTCs to our model: Deutsch's model (D-CTCs) and postselected teleportation
(P-CTCs). We find that D-CTCs reproduce the classical solution multiplicity in
the form of a mixed state, while P-CTCs predict an equal superposition of the
two trajectories, supporting a conjecture by Friedman et al. [Phys. Rev. D 42,
1915 (1990)].
Related papers
- Quantum state tomography on closed timelike curves using weak measurements [0.0]
We show that, for any given combination of chronology-respecting input and unitary interaction, it is always possible to recover the unique state on the P-CTC.
We also demonstrate how this state may be derived from analysis of the P-CTC prescription itself.
arXiv Detail & Related papers (2024-07-19T17:43:27Z) - Quantum clock in the projection evolution formalism [0.0]
We discuss the possibility of constructing a quantum clock, which advances in time during its quantum evolution.
We propose a working two-state model as the simplest example of such a clock.
arXiv Detail & Related papers (2023-11-24T09:56:34Z) - Looking for Carroll particles in two time spacetime [55.2480439325792]
Carroll particles with a non-vanishing value of energy are described in the framework of two time physics.
We construct the quantum theory of such a particle using an unexpected correspondence between our parametrization and that obtained by Bars for the hydrogen atom in 1999.
arXiv Detail & Related papers (2023-10-29T15:51:41Z) - Billiard-ball paradox for a quantum wave packet [0.0]
billiard-ball paradox is a problem involving an object that travels back in time along a closed timelike curve.
We develop a quantum version of the paradox, wherein a (semiclassical) wave packet evolves through a region containing a wormhole time machine.
We discuss the model in the continuum limit, with a particular focus on the various methods one may employ in order to guarantee convergence.
arXiv Detail & Related papers (2022-05-11T10:43:38Z) - Quantum dynamics corresponding to chaotic BKL scenario [62.997667081978825]
Quantization smears the gravitational singularity avoiding its localization in the configuration space.
Results suggest that the generic singularity of general relativity can be avoided at quantum level.
arXiv Detail & Related papers (2022-04-24T13:32:45Z) - The role of fluctuations in quantum and classical time crystals [58.720142291102135]
We study the role of fluctuations on the stability of the system and find no distinction between quantum and classical DTCs.
This allows us to probe the fluctuations in an experiment using two strongly coupled parametric resonators subject to classical noise.
arXiv Detail & Related papers (2022-03-10T19:00:01Z) - Boundary time crystals in collective $d$-level systems [64.76138964691705]
Boundary time crystals are non-equilibrium phases of matter occurring in quantum systems in contact to an environment.
We study BTC's in collective $d$-level systems, focusing in the cases with $d=2$, $3$ and $4$.
arXiv Detail & Related papers (2021-02-05T19:00:45Z) - There is only one time [110.83289076967895]
We draw a picture of physical systems that allows us to recognize what is this thing called "time"
We derive the Schr"odinger equation in the first case, and the Hamilton equations of motion in the second one.
arXiv Detail & Related papers (2020-06-22T09:54:46Z) - Discrete time-crystalline order in Bose-Hubbard model with dissipation [0.0]
discrete time crystal (DTC) can be found only when there exists a meta-stable state in the undriven system.
This paper shows that a $2T$ DTC can appear even when the meta-stable state is absent in the undriven system.
These results might find applications into engineering exotic phases in driven open quantum systems.
arXiv Detail & Related papers (2020-04-08T14:22:22Z) - Projection evolution and quantum spacetime [68.8204255655161]
We discuss the problem of time in quantum mechanics.
An idea of construction of a quantum spacetime as a special set of the allowed states is presented.
An example of a structureless quantum Minkowski-like spacetime is also considered.
arXiv Detail & Related papers (2019-10-24T14:54:11Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.