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Related papers: Classical and quantum stability of higher-derivati…

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The claim that there is an inconsistency of quantum-classical dynamics [1] is investigated. We point out that a consistent formulation of quantum and classical dynamics which can be used to describe quantum measurement processes is already…

Quantum Physics · Physics 2007-05-23 E. C. G. Sudarshan

Experiments violating Bell's inequality appear to indicate deterministic models do not correspond to a realistic theory of quantum mechanics. The theory of pilot waves seemingly overcomes this hurdle via nonlocality and statistical…

Quantum Physics · Physics 2024-05-03 Aminur Rahman

Quantum-corrected equations of motion generically contain higher time derivatives, computed here in the setting of canonically quantized systems. The main example in which detailed derivations are presented is a general anharmonic…

Quantum Physics · Physics 2013-05-30 Martin Bojowald , Suddhasattwa Brahma , Elliot Nelson

We present a simple class of mechanical models where a canonical degree of freedom interacts with another one with a negative kinetic term, i.e. with a ghost. We prove analytically that the classical motion of the system is completely…

General Relativity and Quantum Cosmology · Physics 2021-08-16 Cédric Deffayet , Shinji Mukohyama , Alexander Vikman

A simple mathematical procedure is introduced which allows redefining in an exact way divergent integrals and limits that appear in the basic equations of classical electrodynamics with point charges. In this way all divergences are at once…

Classical Physics · Physics 2015-06-26 Massimo Marino

The relationship between classical and quantum mechanics is usually understood via the limit $\hbar \rightarrow 0$. This is the underlying idea behind the quantization of classical objects. The apparent incompatibility of general relativity…

Quantum Physics · Physics 2021-03-15 J. -B. Bru , W. de Siqueira Pedra

Using the mapping of the Fokker-Planck description of classical stochastic dynamics onto a quantum Hamiltonian, we argue that a dynamical glass transition in the former must have a precise definition in terms of a quantum phase transition…

Statistical Mechanics · Physics 2010-08-10 Claudio Castelnovo , Claudio Chamon , David Sherrington

The physics of many closed, conservative systems can be described by both classical and quantum theories. The dynamics according to classical theory is symplectic and admits linear instabilities which would initially seem at odds with a…

Quantum Physics · Physics 2024-01-08 Michael Q. May , Hong Qin

We give a partial review of what is known so far on stability of periodically driven quantum systems versus regularity of the bounded driven force. In particular we emphasize the fact that unbounded degeneracies of the unperturbed…

Mathematical Physics · Physics 2007-05-23 P. Duclos , O. Lev , P. Stovicek , M. Vittot

Constrained Hamiltonian dynamics of a quantum system of nonlinear oscillators is used to provide the mathematical formulation of a coarse-grained description of the quantum system. It is seen that the evolution of the coarse-grained system…

Quantum Physics · Physics 2015-05-28 Milan Radonjić , Slobodan Prvanović , Nikola Burić

Classical and quantum mechanical descriptions of physical world are seamlessly abridged within the framework of Lagrangian formalism which, besides revealing the essence of nonlocally correlated dynamic evolution, helps understanding abrupt…

Classical Physics · Physics 2024-10-04 D Das

A brief review of the physics of systems including higher derivatives in the Lagrangian is given. All such systems involve ghosts, i.e. the spectrum of the Hamiltonian is not bounded from below and the vacuum ground state is absent. Usually…

High Energy Physics - Theory · Physics 2018-01-17 Andrei Smilga

We study the most general form of a three dimensional classical integrable system with axial symmetry and invariant under the axis reflection. We assume that the three constants of motion are the Hamiltonian, $H$, with the standard form of…

Mathematical Physics · Physics 2009-11-13 M. Gadella , J. Negro , G. P. Pronko

Quantum trajectory techniques have been used in the theory of open systems as a starting point for numerical computations and to describe the monitoring of a quantum system in continuous time. Here we extend this technique and use it to…

Quantum Physics · Physics 2026-05-05 Alberto Barchielli

A kinetic theory for quantum Langmuir waves interacting nonlinearly with quantum ion-acoustic waves is derived. The formulation allows for a statistical analysis of the quantum correction to the Zakharov system. The influence of a…

Plasma Physics · Physics 2009-11-11 M. Marklund

The investigation of quantum-classical correspondence may lead to gain a deeper understanding of the classical limit of quantum theory. We develop a quantum formalism on the basis of a linear-invariant theorem, which gives an exact…

Quantum Physics · Physics 2020-10-20 Jeong Ryeol Choi

The article explores a new formalism for describing motion in quantum mechanics. The construction is based on generalized coherent states with evolving fiducial vector. Weyl-Heisenberg coherent states are utilised to split quantum systems…

General Relativity and Quantum Cosmology · Physics 2020-09-10 Artur Miroszewski

We study the back-reaction of quantum systems onto classical ones. Taking the starting point that semi-classical physics should be described at all times by a point in classical phase space and a quantum state in Hilbert space, we consider…

Quantum Physics · Physics 2024-12-18 Isaac Layton , Jonathan Oppenheim , Zachary Weller-Davies

We extend recent work by Tremblay, Turbiner, and Winternitz which analyzes an infinite family of solvable and integrable quantum systems in the plane, indexed by the positive parameter k. Key components of their analysis were to demonstrate…

Mathematical Physics · Physics 2015-05-14 E. G. Kalnins , W. Miller , G. S. Pogosyan

We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless''…

General Relativity and Quantum Cosmology · Physics 2015-06-25 H. -T. Elze