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Related papers: Finite Quantum Dynamics

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An exact invariant is derived for $n$-degree-of-freedom Hamiltonian systems with general time-dependent potentials. The invariant is worked out in two equivalent ways. In the first approach, we define a special {\it Ansatz\/} for the…

Classical Physics · Physics 2023-03-23 Jürgen Struckmeier , Claus Riedel

This paper studies the energy decoherence of an interacting quantum system. It first reviews the experiments that motivated the postulates of quantum mechanics. It then discusses a decoherence that occurs dynamically in a closed system.…

Quantum Physics · Physics 2024-12-03 Henry Crumley

We characterize the conditions under which a multi-time quantum process with a finite temporal resolution can be approximately described by an equilibrium one. By providing a generalization of the notion of equilibration on average, where a…

Quantum Physics · Physics 2020-10-02 Pedro Figueroa-Romero , Kavan Modi , Felix A. Pollock

It is shown that a coherent understanding of all quantized phenomena, including those governed by unitary evolution equations as well as those related to irreversible quantum measurements, can be achieved in a scenario of successive…

Quantum Physics · Physics 2007-12-31 Xiaolei Zhang

Developing an earlier proposal (Ne'eman, Damnjanovic, etc), we show herein that there is a Landau continuous phase transition from the exact quantum dynamics to the effectively classical one, occurring via spontaneous superposition breaking…

Quantum Physics · Physics 2007-05-23 Vladan Pankovic , Tristan Hubsch , Milan Predojevic , Miodrag Krmar

We investigate the monitored quantum dynamics of Gaussian mixed states and derive the universal Fokker-Planck equations that govern the stochastic time evolution of entire density-matrix spectra, obtaining their exact solutions. From these…

Statistical Mechanics · Physics 2025-04-24 Zhenyu Xiao , Tomi Ohtsuki , Kohei Kawabata

The quantum description of time evolution in non-linear gravitational systems such as cosmological space-times is not well understood. We show, in the simplified setting of mini-superspace, that time evolution of this system can be obtained…

General Relativity and Quantum Cosmology · Physics 2023-05-02 Anne-Katherine Burns , David E. Kaplan , Tom Melia , Surjeet Rajendran

We investigate quantum correlations in time in different approaches. We assume that temporal correlations should be treated in an even-handed manner with spatial correlations. We compare the pseudo-density matrix formalism with several…

Quantum Physics · Physics 2020-12-23 Tian Zhang , Oscar Dahlsten , Vlatko Vedral

Quantum dissipation in thermal environment is investigated, using the path integral approach. The reduced density matrix of the harmonic oscillator system coupled to thermal bath of oscillators is derived for arbitrary spectrum of bath…

High Energy Physics - Theory · Physics 2009-10-30 I. Joichi , Sh. Matsumoto , M. Yoshimura

We explore the consequences of requiring that quantum theories of gravity be unitary, mostly focusing on simple cosmological models to illustrate the main points. We show that unitarity for a clock that encounters a classical singularity at…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Steffen Gielen , Lucía Menéndez-Pidal

The framework of entropic dynamics (ED) allows one to derive quantum mechanics as an application of entropic inference. In this work we derive the classical limit of quantum mechanics in the context of ED. Our goal is to find conditions so…

Quantum Physics · Physics 2017-08-01 Anthony Demme , Ariel Caticha

We analyze the quantization of dynamical systems that do not involve any background notion of space and time. We give a set of conditions for the introduction of an intrinsic time in quantum mechanics. We show that these conditions are a…

High Energy Physics - Theory · Physics 2011-08-19 Ricardo Doldan , Pablo Mora , Rodolfo Gambini

This letter explores how a reinterpretation of the generalized uncertainty principle as an effective variation of Planck's constant provides a physical explanation for a number of fundamental quantities and couplings. In this context, a…

General Physics · Physics 2024-09-02 Ahmed Farag Ali , Jonas Mureika , Elias C. Vagenas , Ibrahim Elmashad

In previous works, we showed that both time and space can emerge from entanglement within a globally constrained quantum Universe, with no background coordinates. By extending the Page and Wootters quantum time formalism to include both…

General Relativity and Quantum Cosmology · Physics 2025-09-30 Tommaso Favalli

Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do…

Quantum Physics · Physics 2010-05-06 John Ashmead

When quantum back-reaction by fluctuations, correlations and higher moments of a state becomes strong, semiclassical quantum mechanics resembles a dynamical system with a high-dimensional phase space. Here, systematic computational methods…

General Relativity and Quantum Cosmology · Physics 2011-09-13 Martin Bojowald , David Brizuela , Hector H. Hernandez , Michael J. Koop , Hugo A. Morales-Tecotl

The time dependence of one-dimensional quantum mechanical probability densities is presented when the potential in which a particle moves is suddenly changed, called a quench. Quantum quenches are mainly addressed but a comparison with…

Quantum Physics · Physics 2024-06-18 K. Schönhammer

Treating the time of an event as a quantum variable, we derive a scheme in which superpositions in time are used to perform operations in an indefinite causal order. We use some aspects of a recently developed space-time-symmetric formalism…

Quantum Physics · Physics 2022-07-13 David Felce , Nicetu Tibau Vidal , Vlatko Vedral , Eduardo O. Dias

We consider a periodic quantum clock based on cooperative resonance fluorescence at zero temperature. In the quantum case, this system has an exact steady state and the limit cycle appears in conditional quantum dynamics under homodyne…

Quantum Physics · Physics 2025-03-18 Varinder Singh , Euijoon Kwon , G J Milburn

Thermodynamic constraints impose a trade-off between power and efficiency in heat engines, preventing the simultaneous achievement of high power and high efficiency. For classical microscopic engines, explicit inequalities have been…

Statistical Mechanics · Physics 2025-01-22 Hyun-Myung Chun , Jong-Min Park