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In a previous paper, the author proposed a quantum mechanical interaction that would insure that the evolution of subjective states would parallel the evolution of biological states, as required by von Neumann's theory of measurement. The…

Quantum Physics · Physics 2007-05-23 Richard A. Mould

An extension of standard quantum mechanics is proposed in which the Newtonian time appearing as a parameter in the unitary evolution operator is replaced with the time shown by a `quantum clock'. Such a clock is defined by the following…

Quantum Physics · Physics 2026-03-17 Dorje C. Brody , Lane P. Hughston

We take a new look at the DeWitt equation, a defining equation for the effective action functional in quantum field theory. We present a formal solution to this equation, and discuss the equation in various contexts, and in particular for…

High Energy Physics - Theory · Physics 2013-06-05 Parikshit Dutta , Krzysztof A. Meissner , Hermann Nicolai

The unitary operators U(t), describing the quantum time evolution of systems with a time-dependent Hamiltonian, can be constructed in an explicit manner using the method of time-dependent invariants. We clarify the role of Lie-algebraic…

Mathematical Physics · Physics 2008-05-30 Maciej Kuna , Jan Naudts

Koopman and von Neumann (KvN) extended the Liouville equation by introducing a phase space function $S^{(K)}(q,p,t)$ whose physical meaning is unknown. We show that a different $S(q,p,t)$, with well-defined physical meaning, may be…

Quantum Physics · Physics 2018-05-21 Ulf Klein

In the study of open quantum systems modeled by a unitary evolution of a bipartite Hilbert space, we address the question of which parts of the environment can be said to have a "classical action" on the system, in the sense of acting as a…

Mathematical Physics · Physics 2015-11-30 Ivan Bardet

A modification of the Fokker action is proposed, which allows one to formulate the covariant quantum theory of the charge system, in which the proper time of each particle serves as the evolution parameter and the particles themselves…

Quantum Physics · Physics 2020-04-22 Natalia Gorobey , Alexander Lukyanenko , A. V. Goltsev

It is shown that the existence of a time operator in the Liouville space representation of both classical and quantum evolution provides a mechanism for effective entropy change of physical states. In particular, an initially effectively…

Quantum Physics · Physics 2016-09-08 Eli Eisenberg , Larry Horwitz

We construct a descriptive toy model that considers quantum effects on biological evolution starting from Chaitin's classical framework. There are smart evolution scenarios in which a quantum world is as favorable as classical worlds for…

Quantum Physics · Physics 2012-03-26 M. A. Martin-Delgado

The time evolution of correlation functions in statistical systems is described by an exact functional differential equation for the corresponding generating functionals. This allows for a systematic discussion of non-equilibrium physics…

High Energy Physics - Theory · Physics 2009-10-30 Christof Wetterich

This paper presents a novel formalism for the out of equilibrium dynamics of the density matrix, capable of describing highly entangled many-body interactions. The evolution of quantum states is evaluated via eigenvalue dynamics of a…

Quantum Physics · Physics 2025-10-28 Mumnuna Aziz Qureshi

We derive a new exact evolution equation for the scale dependence of an effective action. The corresponding equation for the effective potential permits a useful truncation. This allows one to deal with the infrared problems of theories…

High Energy Physics - Theory · Physics 2017-10-17 Christof Wetterich

We study a first-order formulation for the coupled evolution of a quantum scalar field and a classical Friedmann universe. The model is defined by a state dependent hamiltonian constraint and the time dependent Schr\"odinger equation for…

General Relativity and Quantum Cosmology · Physics 2021-12-20 Viqar Husain , Suprit Singh

The dynamical behavior of interacting systems plays a fundamental role for determining quantum correlations, such as entanglement. In this Letter, we describe temporal quantum effects of the inseparable evolution of composite quantum states…

Quantum Physics · Physics 2017-10-26 J. Sperling , I. A. Walmsley

Using the fact that any linear representation of a group can be embedded into permutations, we propose a constructive description of quantum behavior that provides, in particular, a natural explanation of the appearance of complex numbers…

Quantum Physics · Physics 2016-03-24 Vladimir V. Kornyak

In this work, we proposed a smooth transition wave equation from a quantum to classical regime in the framework of von Neumann formalism for ensembles and then obtained an equivalent scaled equation. This led us to develop a scaled…

Quantum Physics · Physics 2023-06-05 S. V. Mousavi , S. Miret-Artés

We employ the equal-time formulation of quantum field theory to derive effective kinetic theories, first for a weakly coupled non-relativistic Bose gas, and then for a strongly correlated system of self-interacting N-component fields. Our…

Quantum Gases · Physics 2022-04-14 Robert Ott , Torsten V. Zache , Jürgen Berges

The von Neumann evolution equation for density matrix and the Moyal equation for the Wigner function are mapped onto evolution equation for optical tomogram of quantum state. The connection with known evolution equation for symplectic…

Quantum Physics · Physics 2011-01-14 Ya. A. Korennoy , V. I. Man'ko

We use the so-called Liouville-von Neumann (LvN) approach to study the nonequilibrium quantum dynamics of time-dependent second order phase transitions. The LvN approach is a canonical method that unifies the functional Schr\"{o}dinger…

High Energy Physics - Phenomenology · Physics 2009-10-31 Sang Pyo Kim , Chul H. Lee

A quantum-classical limit of the canonical equilibrium time correlation function for a quantum system is derived. The quantum-classical limit for the dynamics is obtained for quantum systems comprising a subsystem of light particles in a…

Statistical Mechanics · Physics 2009-11-10 Alessandro Sergi , Raymond Kapral