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Related papers: Computability Theory of Closed Timelike Curves

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We study the paradoxical aspects of closed time-like curves and their impact on the theory of computation. After introducing the $\text{TM}_\text{CTC}$, a classical Turing machine benefiting CTCs for backward time travel, Aaronson et al.…

Computational Complexity · Computer Science 2023-01-30 Sara Babaee Khanehsar , Farzad Didehvar

We examine some variants of computation with closed timelike curves (CTCs), where various restrictions are imposed on the memory of the computer, and the information carrying capacity and range of the CTC. We give full characterizations of…

Computational Complexity · Computer Science 2014-01-29 A. C. Cem Say , Abuzer Yakaryilmaz

While closed timelike curves (CTCs) are not known to exist, studying their consequences has led to nontrivial insights in general relativity, quantum information, and other areas. In this paper we show that if CTCs existed, then quantum…

Quantum Physics · Physics 2009-11-13 Scott Aaronson , John Watrous

Closed Timelike Curves are relativistically valid objects allowing time travel to the past. Treating them as computational objects opens the door to a wide range of results which cannot be achieved using non relativistic quantum mechanics.…

Quantum Physics · Physics 2019-01-25 Soumik Ghosh , Arnab Adhikary , Goutam Paul

Many results have been recently obtained regarding the power of hypothetical closed time-like curves (CTCs) in quantum computation. Here we show that the one-way model of measurement-based quantum computation encompasses in a natural way…

Quantum Physics · Physics 2011-01-27 Raphael Dias da Silva , Ernesto F. Galvao , Elham Kashefi

Closed timelike curves (CTCs) are trajectories in spacetime that effectively travel backwards in time: a test particle following a CTC can in principle interact with its former self in the past. CTCs appear in many solutions of Einstein's…

Quantum computation with quantum data that can traverse closed timelike curves represents a new physical model of computation. We argue that a model of quantum computation in the presence of closed timelike curves can be formulated which…

Quantum Physics · Physics 2008-11-26 Dave Bacon

This paper discusses the quantum mechanics of closed timelike curves (CTC) and of other potential methods for time travel. We analyze a specific proposal for such quantum time travel, the quantum description of CTCs based on post-selected…

Quantum Physics · Physics 2011-07-15 Seth Lloyd , Lorenzo Maccone , Raul Garcia-Patron , Vittorio Giovannetti , Yutaka Shikano

A computer which has access to a closed timelike curve, and can thereby send the results of calculations into its own past, can exploit this to solve difficult computational problems efficiently. I give a specific demonstration of this for…

General Relativity and Quantum Cosmology · Physics 2022-02-04 Todd A. Brun

In this paper, we investigate the possibility of using closed timelike curves (CTCs) in relativistic hypercomputation. We introduce a wormhole based hypercomputation scenario which is free from the common worries, such as the blueshift…

General Relativity and Quantum Cosmology · Physics 2012-11-27 Hajnal Andréka , István Németi , Gergely Székely

One way to study the physical plausibility of closed timelike curves (CTCs) is to examine their computational power. This has been done for Deutschian CTCs (D-CTCs) and post-selection CTCs (P-CTCs), with the result that they allow for the…

Quantum Physics · Physics 2025-03-07 Mateus Araújo , Philippe Allard Guérin , Ämin Baumeler

Proposed models of closed timelike curves (CTCs) have been shown to enable powerful information-processing protocols. We examine the simulation of models of CTCs both by other models of CTCs and by physical systems without access to CTCs.…

Quantum Physics · Physics 2017-02-28 Todd A. Brun , Mark M. Wilde

One out of many emerging implications from solutions of Einstein's general relativity equations are closed timelike curves (CTCs), which are trajectories through spacetime that allow for time travel to the past without exceeding the speed…

General Relativity and Quantum Cosmology · Physics 2019-02-13 Małgorzata Bartkiewicz , Andrzej Grudka , Ryszard Horodecki , Justyna Łodyga , Jacek Wychowaniec

The fact that closed timelike curves (CTCs) are permitted by general relativity raises the question as to how quantum systems behave when time travel to the past occurs. Research into answering this question by utilising the quantum circuit…

Quantum Physics · Physics 2014-10-13 John-Mark A. Allen

We study the nature of entanglement in presence of Deutschian closed timelike curves (D-CTCs) and we observe that qubits traveling along a D-CTC allow unambiguous discrimination of Bell states with Local Operations and Classical…

Quantum Physics · Physics 2022-10-20 Subhayan Roy Moulick , Prasanta K. Panigrahi

Computational problems are classified into computable and uncomputable problems. If there exists an effective procedure (algorithm) to compute a problem then the problem is computable otherwise it is uncomputable. Turing machines can…

Computational Complexity · Computer Science 2024-09-06 Asad Khaliq

The possible existence of closed timelike curves (CTCs) draws attention to fundamental questions about what is physically possible and what is not. An example is the "no cloning theorem" in quantum mechanics, which states that no physical…

Quantum Physics · Physics 2015-06-19 D. Ahn , T. C. Ralph , R. B. Mann

We investigate the relationship between computation and spacetime structure, focussing on the role of closed timelike curves (CTCs) in promoting computational speedup. We note first that CTC traversal can be interpreted in two distinct…

General Relativity and Quantum Cosmology · Physics 2011-03-08 Mike Stannett

Inspired by Quantum Mechanics, we reformulate Hilbert's tenth problem in the domain of integer arithmetics into problems involving either a set of infinitely-coupled non-linear differential equations or a class of linear Schr\"odinger…

General Mathematics · Mathematics 2007-05-23 Tien D. Kieu

We consider causality respecting (CR) quantum systems interacting with closed timelike curves (CTCs), within the Deutsch model. We introduce the concepts of popping up and elimination of quantum information and use them to show that…

Quantum Physics · Physics 2018-07-17 Asutosh Kumar , Indranil Chakrabarty , Arun Kumar Pati , Aditi Sen De , Ujjwal Sen
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