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A new formulation of quantum mechanics based on differential commutator brackets is developed. We have found a wave equation representing the fermionic particle. In this formalism, the continuity equation mixes the Klein-Gordon and…

General Physics · Physics 2012-03-21 Arbab I. Arbab , Faisal A. Yassein

We have developed a variational perturbation theory based on the Liouville-Neumann equation, which enables one to systematically compute the perturbative correction terms to the variationally determined wave functions of the time-dependent…

High Energy Physics - Theory · Physics 2008-11-26 Dongsu Bak , Sang Pyo Kim , Sung Ku Kim , Kwang-Sup Soh , Jae Hyung Yee

Variational formulations of time-dependent PDEs in space and time yield $(d+1)$-dimensional problems to be solved numerically. This increases the number of unknowns as well as the storage amount. On the other hand, this approach enables…

Numerical Analysis · Mathematics 2019-12-24 Julian Henning , Davide Palitta , Valeria Simoncini , Karsten Urban

In this paper, we present a variational treatment of the linear dependence for a non-orthogonal time-dependent basis set in solving the Schr\"odinger equation. The method is based on: i) the definition of a linearly independent working…

Quantum Physics · Physics 2022-10-12 Loïc Joubert-Doriol

We derive a systematic high-frequency expansion for the effective Hamiltonian and the micromotion operator of periodically driven quantum systems. Our approach is based on the block diagonalization of the quasienergy operator in the…

Quantum Gases · Physics 2015-09-25 André Eckardt , Egidijus Anisimovas

In this paper, we consider the classical wave equation with time-dependent, spatially multiscale coefficients. We propose a fully discrete computational multiscale method in the spirit of the localized orthogonal decomposition in space with…

Numerical Analysis · Mathematics 2021-07-30 Bernhard Maier , Barbara Verfürth

We propose a new analytical method to solve for nonexactly soluble Schrodinger equation via expansions through some existing quantum numbers. Successfully, it is applied to the rational non-polynomial oscillator potential. Moreover, a…

Mathematical Physics · Physics 2007-05-23 Omar Mustafa , Maen Odeh

In order to find analytically the travelling waves of partially integrable autonomous nonlinear partial differential equations, many methods have been proposed over the ages: "projective Riccati method", "tanh-method", "exponential method",…

Classical Analysis and ODEs · Mathematics 2017-10-16 Robert Conte , Micheline Musette

A local approach to the time integration of PDEs by exponential methods is proposed, motivated by theoretical estimates by A.Iserles on the decay of off-diagonal terms in the exponentials of sparse matrices. An overlapping domain…

Numerical Analysis · Mathematics 2015-05-12 Luca Bonaventura

We substantially extend our relaxation theory for perturbed many-body quantum systems from [Phys. Rev. Lett. 124, 120602 (2020)] by establishing an analytical prediction for the time-dependent observable expectation values which depends on…

Statistical Mechanics · Physics 2021-01-12 Lennart Dabelow , Peter Reimann

The machine learning explosion has created a prominent trend in modern computer hardware towards low precision floating-point operations. In response, there have been growing efforts to use low and mixed precision in general scientific…

Numerical Analysis · Mathematics 2024-03-19 Cody J. Balos , Steven Roberts , David J. Gardner

In this paper, a family of arbitrarily high-order structure-preserving exponential Runge-Kutta methods are developed for the nonlinear Schr\"odinger equation by combining the scalar auxiliary variable approach with the exponential…

Numerical Analysis · Mathematics 2020-09-15 Jin Cui , Zhuangzhi Xu , Yushun Wang , Chaolong Jiang

Both the classical time-ordering and the Magnus expansion are well-known in the context of linear initial value problems. Motivated by the noncommutativity between time-ordering and time derivation, and related problems raised recently in…

Mathematical Physics · Physics 2013-03-12 Michel Bauer , Raphael Chetrite , Kurusch Ebrahimi-Fard , Frederic Patras

We analyze the problem of one dimensional quantum particle falling in a constant gravitational field, also known as the {\it bouncing ball}, employing a semiclassical approach known as momentous effective quantum mechanics. In this…

Quantum Physics · Physics 2019-04-16 Guillermo Chacon-Acosta , Hector Hernandez-Hernandez , Mercedes Velazquez

We investigate the Magnus expansion for a generic time-dependent two-level system under single-axis driving.By virtue of the su(2) Lie algebra, the expansion is decomposed into a commutator-free form. To illustrate the usefulness of the…

Quantum Physics · Physics 2026-05-14 Chen Wei , Frank Großmann

Time-dependent linear differential equations are a common type of problem that needs to be solved in classical physics. Here we provide a quantum algorithm for solving time-dependent linear differential equations with logarithmic dependence…

Quantum Physics · Physics 2024-06-19 Dominic W. Berry , Pedro C. S. Costa

Solutions in the form of series expansion, as the Born approximation, are very useful for describing time-independent scattering of quantum particles. In this work, it is mathematically demonstred that such solutions, when applied to…

Materials Science · Physics 2009-11-10 Sérgio L. Morelhão , Luis H. Avanci , Stefan Kycia

We consider a system of classical Brownian particles interacting via a smooth long-range potential in the mean-field regime, and we analyze the propagation of chaos in form of sharp, uniform-in-time estimates on many-particle correlation…

Analysis of PDEs · Mathematics 2025-02-18 Armand Bernou , Mitia Duerinckx

Time-dependent quantum mechanics provides an intuitive picture of particle propagation in external fields. Semiclassical methods link the classical trajectories of particles with their quantum mechanical propagation. Many analytical results…

Mesoscale and Nanoscale Physics · Physics 2008-03-07 Tobias Kramer , Eric J. Heller , Robert E. Parrott

We analyse and compare several algorithms to compute numerically periodic solutions of high-dimensional dynamical systems and investigate their Floquet stability without building the monodromy matrix. The solution and its perturbation are…

Fluid Dynamics · Physics 2025-06-17 Artur Gesla , Yohann Duguet , Patrick Le Quéré , Laurent Martin Witkowski