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Related papers: On the Space-Time Geometry of Quantum Systems

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We study the time evolution of early universe which is developed by a cosmological constant $\Lambda_4$ and supersymmetric Yang-Mills (SYM) fields in the Friedmann-Robertson-Walker (FRW) space-time. The renormalized vacuum expectation value…

High Energy Physics - Theory · Physics 2018-04-04 Kazuo Ghoroku , Yoshimasa Nakano , Motoi Tachibana , Fumihiko Toyoda

We develop a geometric description of quantum light in photonic time crystals on the SU(1,1) coherent-state manifold. In a projective picture, the evolution of each mode appears as a M\"obius isometry on the Poincar\'e disk, where…

We treat space and time as bona fide quantum degrees of freedom on an equal footing in Hilbert space. Motivated by considerations in quantum gravity, we focus on a paradigm dealing with linear, first-order Hamiltonian and momentum…

Quantum Physics · Physics 2022-01-19 Ashmeet Singh

It is known that quantum field theories in curved spacetime suffer from a number of pathologies, including the inability to relate states on different spatial slices by proper unitary time-evolution operators. In this article, we illustrate…

High Energy Physics - Theory · Physics 2025-12-19 William T. Emond , Christian Käding , Peter Millington

Simulating time evolution of generic quantum many-body systems using classical numerical approaches has an exponentially growing cost either with evolution time or with the system size. In this work, we present a polynomially scaling hybrid…

Quantum Physics · Physics 2023-09-18 Nikita Astrakhantsev , Sheng-Hsuan Lin , Frank Pollmann , Adam Smith

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

Hamiltonian mechanics describes the evolution of a system through its Hamiltonian. The Hamiltonian typically also represents the energy observable, a Noether-conserved quantity associated with the time-invariance of the law of evolution. In…

Quantum Physics · Physics 2024-03-29 Libo Jiang , Daniel R. Terno , Oscar Dahlsten

We propose a fibre bundle formulation of the mathematical base of relativistic quantum mechanics. At the present stage the bundle form of the theory is equivalent to its conventional one, but it admits new types of generalizations in…

Quantum Physics · Physics 2007-05-23 Bozhidar Z. Iliev

The understanding of time and dynamics can be elucidated by examining the concept of entanglement in quantum theory. This particular perspective on time is referred to as the timeless approach, which posits that the universe exists in a…

General Relativity and Quantum Cosmology · Physics 2023-12-07 H. Hadi , F. Darabi , K. Atazadeh

A ring resonator involves a scattering process where a part of the output is fed again into the input. The same formal structure is encountered in the problem of time travel in a neighborhood of a closed timelike curve (CTC). We know how to…

Quantum Physics · Physics 2022-07-19 Marek Czachor

This work concerns a study of the quantum mechanical extension of the work of Horwitz et al. [1] on the stability of classical Hamiltonian systems by geometrical methods. Simulations are carried out for several important examples, these…

Quantum Physics · Physics 2017-04-12 Gil Elgressy , Lawrence Horwitz

The dynamical aspects of a spin-1/2 particle in Hermitian coquaternionic quantum theory is investigated. It is shown that the time evolution exhibits three different characteristics, depending on the values of the parameters of the…

Mathematical Physics · Physics 2015-03-19 Dorje C. Brody , Eva-Maria Graefe

The Entropic Dynamics reconstruction of quantum mechanics is extended to quantum field theory in curved space-time. The Entropic Dynamics framework, which derives quantum theory as an application of the method of maximum entropy, is…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Selman Ipek , Mohammad Abedi , Ariel Caticha

As time passes, once simple quantum states tend to become more complex. For strongly coupled k-local Hamiltonians, this growth of computational complexity has been conjectured to follow a distinctive and universal pattern. In this paper we…

High Energy Physics - Theory · Physics 2017-02-28 Adam R. Brown , Leonard Susskind , Ying Zhao

Several conceptual aspects of quantum gravity are studied on the example of the homogeneous isotropic LQC model. In particular: $(i)$ The proper time of the co-moving observers is showed to be a quantum operator {and} a quantum spacetime…

General Relativity and Quantum Cosmology · Physics 2009-01-27 Wojciech Kaminski , Jerzy Lewandowski , Tomasz Pawlowski

In quantum mechanics, time is introduced as a non-measurable quantity, as there is no possibility to build a hermitian operator canonically conjugated to the Hamiltonian. We cannot have, therefore, the time operator, which means that the…

Quantum Physics · Physics 2020-03-27 Andrzej Góźdź , Marek Góźdź

We construct concrete examples of time operators for both continuous and discrete-time homogeneous quantum walks, and we determine their deficiency indices and spectra. For a discrete-time quantum walk, the time operator can be self-adjoint…

Mathematical Physics · Physics 2020-06-23 Daiju Funakawa , Yasumichi Matsuzawa , Akito Suzuki , Itaru Sasaki , Noriaki Teranishi

We characterize good clocks, which are naturally subject to fluctuations, in statistical terms. We also obtain the master equation that governs the evolution of quantum systems according to these clocks and find its general solution. This…

Quantum Physics · Physics 2009-10-31 Inigo L. Egusquiza , Luis J. Garay , Jose M. Raya

Consistent dynamics which couples classical and quantum degrees of freedom exists, provided it is stochastic. This dynamics is linear in the hybrid state, completely positive and trace preserving. One application of this is to study the…

Quantum Physics · Physics 2023-01-04 Jonathan Oppenheim , Carlo Sparaciari , Barbara Šoda , Zachary Weller-Davies

Rovelli's `` quantum mechanics without time'' motivates an intrinsically time-slicing independent picture of reduced phase space quantum gravity, which may be described as ``quantization after evolution''. Sufficient criteria for carrying…

General Relativity and Quantum Cosmology · Physics 2009-10-28 R. Cosgrove
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