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Related papers: Generalized Quantum Dynamics with Arrow of Time

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We present a quantum algorithm for the dynamical simulation of time-dependent Hamiltonians. Our method involves expanding the interaction-picture Hamiltonian as a sum of generalized permutations, which leads to an integral-free Dyson series…

Quantum Physics · Physics 2021-09-15 Yi-Hsiang Chen , Amir Kalev , Itay Hen

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 appearance of Hamiltonian constraint in the canonical formalism for general relativity reflects the lack of a fixed external time. The dynamics of general relativistic systems can be expressed with respect to an arbitrarily chosen…

General Relativity and Quantum Cosmology · Physics 2017-09-21 Przemyslaw Malkiewicz

We develop a technique for finding the dynamical evolution in time of an averaged density matrix. The result is an equation of evolution that includes an Effective Hamiltonian, as well as decoherence terms in Lindblad form. Applying the…

Quantum Physics · Physics 2013-03-28 Omar Gamel , Daniel F. V. James

In this paper, we derive equations of motion for the normal-order, the symmetric-order and the antinormal-order quantum characteristic functions, applicable for general Hamiltonian systems. We do this by utilizing the `characteristic form'…

Quantum Physics · Physics 2008-05-02 Itay Hen , Amir Kalev

We propose an operator constraint equation for the wavefunction of the Universe that admits genuine evolution. While the corresponding classical theory is equivalent to the canonical decomposition of General Relativity, the quantum theory…

General Relativity and Quantum Cosmology · Physics 2014-04-03 Sean Gryb , Karim Thebault

We provide a Hilbert space approach to quantum mechanics where space and time are treated on an equal footing. Our approach replaces the standard dependence on an external classical time parameter with a spacetime-symmetric algebraic…

Quantum Physics · Physics 2026-02-10 N. L. Diaz , R. Rossignoli

Quantum timeless approaches solve the problem of time by recovering the usual unitary evolution of quantum theory relative to a clock in a stationary quantum Universe. For some Hamiltonians of the Universe, such as those including an…

Quantum Physics · Physics 2026-04-14 Simone Rijavec

We investigate the thermodynamic arrow of time in a time-symmetrically recollapsing universe by calculating quantum mechanically the entropy production of a massive scalar field. It is found that even though the Hamiltonian has a…

General Relativity and Quantum Cosmology · Physics 2011-04-15 Sang Pyo Kim

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

One of the axioms of quantum field theory is the property of unitarity of the evolution operator. However, if one considers the quantum electrodynamics in the external field in the leading order of perturbation theory, one will find that…

High Energy Physics - Theory · Physics 2008-11-26 O. Yu. Shvedov

Deriving an arrow of time from time-reversal symmetric microscopic dynamics is a fundamental open problem in many areas of physics, ranging from cosmology, to particle physics, to thermodynamics and statistical mechanics. Here we focus on…

Quantum Physics · Physics 2025-01-31 Thomas Guff , Chintalpati Umashankar Shastry , Andrea Rocco

The thermodynamics of quantum systems coupled to periodically modulated heat baths and work reservoirs is developed. By identifying affinities and fluxes, the first and second law are formulated consistently. In the linear response regime,…

Statistical Mechanics · Physics 2016-06-29 Kay Brandner , Udo Seifert

We present efficient quantum algorithms for simulating time-dependent Hamiltonian evolution of general input states using an oracular model of a quantum computer. Our algorithms use either constant or adaptively chosen time steps and are…

Quantum Physics · Physics 2011-11-03 Nathan Wiebe , Dominic W. Berry , Peter Hoyer , Barry C. Sanders

In some recent papers, the so called $(H,\rho)$-induced dynamics of a system $\mathcal{S}$ whose time evolution is deduced adopting an operatorial approach, has been introduced. According to the formal mathematical apparatus of quantum…

Mathematical Physics · Physics 2021-08-05 Rosa Di Salvo , Matteo Gorgone , Francesco Oliveri

Let us imagine that there is an overall quantum theory (not necessarily recognized yet) of matter and energy ({\it i.e.}, of elementary fermions and bosons) interacting with the physical spacetime (treated on a quantum level). Since states…

High Energy Physics - Theory · Physics 2007-05-23 Wojciech Krolikowski

The second law of thermodynamics - the usual statement of the arrow of time - has been called the most fundamental law of physics. It is thus difficult to conceive that a single dynamical system could contain subsystems, in significant…

Statistical Mechanics · Physics 2007-05-23 L. S. Schulman

We propose a generalization of Heisenberg picture quantum mechanics in which a Lagrangian and Hamiltonian dynamics is formulated directly for dynamical systems on a manifold with non--commuting coordinates, which act as operators on an…

High Energy Physics - Theory · Physics 2010-11-01 Stephen L. Adler

We investigate the statistical arrow of time for a quantum system being monitored by a sequence of measurements. For a continuous qubit measurement example, we demonstrate that time-reversed evolution is always physically possible, provided…

Quantum Physics · Physics 2017-12-06 Justin Dressel , Areeya Chantasri , Andrew N. Jordan , Alexander N. Korotkov

It has been argued that it is incompatible to maintain unitary time-evolution for time-dependent non-Hermitian Hamiltonians when the metric operator is explicitly time-dependent. We demonstrate here that the time-dependent Dyson equation…

Quantum Physics · Physics 2016-04-27 Andreas Fring , Miled H. Y. Moussa