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We present a simple algebraic procedure that can be applied to solve a range of quantum eigenvalue problems without the need to know the solution of the Schr\"odinger equation. The procedure, presented with a pedagogical purpose, is based…

Quantum Physics · Physics 2021-11-17 Luis de la Peña , Ana María Cetto , Andrea Valdés-Hernández

Numerical stochastic perturbation theory is a powerful tool for estimating high-order perturbative expansions in lattice field theory. The standard algorithms based on the Langevin equation, however, suffer from several limitations which in…

High Energy Physics - Lattice · Physics 2017-09-11 Mattia Dalla Brida , Marco Garofalo , A. D. Kennedy

We propose a numerical method for evaluating eigenvalues and eigenfunctions of Schr\"odinger operators with general confining potentials. The method is selective in the sense that only the eigenvalue closest to a chosen input energy is…

Quantum Physics · Physics 2009-10-28 Carlo Presilla , Ubaldo Tambini

The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously…

High Energy Physics - Lattice · Physics 2017-06-02 Mattia Dalla Brida , Martin Lüscher

We develop new perturbation techniques for conducting convergence analysis of various first-order algorithms for a class of nonsmooth optimization problems. We consider the iteration scheme of an algorithm to construct a perturbed…

Optimization and Control · Mathematics 2018-10-25 Xiangfeng Wang , Jane Ye , Xiaoming Yuan , Shangzhi Zeng , Jin Zhang

Second-order self-force computations, which will be essential in modeling extreme-mass-ratio inspirals, involve two major new difficulties that were not present at first order. One is the problem of large scales, discussed in [Phys. Rev. D…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Jeremy Miller , Barry Wardell , Adam Pound

Quantum subspace diagonalization methods are an exciting new class of algorithms for solving large\rev{-}scale eigenvalue problems using quantum computers. Unfortunately, these methods require the solution of an ill-conditioned generalized…

Quantum Physics · Physics 2023-06-16 Ethan N. Epperly , Lin Lin , Yuji Nakatsukasa

We report a new analytical method for solution of a wide class of second-order differential equations with eigenvalues replaced by arbitrary functions. Such classes of problems occur frequently in Quantum Mechanics and Optics. This approach…

Mathematical Physics · Physics 2012-04-30 Sina Khorasani

The first order by time partial differential equations are used as models in applications such as fluid flow, heat transfer, solid deformation, electromagnetic waves, and others. In this paper we propose the new numerical method to solve a…

Numerical Analysis · Mathematics 2008-01-14 Ivan Kazachkov

In this paper we prove the existence of solutions for a second order sweeping process with a Lipschitz single valued perturbation by transforming it to a first order problem.

Classical Analysis and ODEs · Mathematics 2019-10-11 Fatine Aliouane , Dalila Azzam-Laouir

In this paper, we will introduce a high order numerical method to solve the scattering problems with non-periodic incident fields and (locally perturbed) periodic surfaces. For the problems we are considering, the classical methods to treat…

Numerical Analysis · Mathematics 2018-07-26 Ruming Zhang

The explicit semiclassical treatment of logarithmic perturbation theory for the bound-state problem within the framework of the radial Klein-Gordon equation with attractive real-analytic screened Coulomb potentials, contained time-component…

Quantum Physics · Physics 2007-05-23 I. V. Dobrovolska , R. S. Tutik

We present an application of a nonstandard approximate method---the finite-rank approximation---to solving the time-independent Schr\"odinger equation for a bound-state problem. The method is illustrated on the example of a…

Quantum Physics · Physics 2014-09-18 Vladimir B. Belyaev , Andrej Babič

In this paper we develop a new approximation method valid for a wide family of nonlinear wave equations of Nonlinear Schr\"odinger type. The result is a reduced set of ordinary differential equations for a finite set of parameters measuring…

patt-sol · Physics 2007-05-23 J. J. Garcia-Ripoll , V. M. Perez-Garcia

One of the most common problems of scientific applications is computation of the derivative of a function specified by possibly noisy or imprecise experimental data. Application of conventional techniques for numerically calculating…

Functional Analysis · Mathematics 2015-04-14 Ildar R. Muftahov , Denis N. Sidorov , Nikolai A. Sidorov

We investigate the increasing stability of the inverse Schr\"{o}dinger potential problem with integer power type nonlinearities at a large wavenumber. By considering the first order linearized system with respect to the unknown potential…

Analysis of PDEs · Mathematics 2024-10-07 Sen Zou , Shuai Lu , Boxi Xu

In this paper a novel numerical approximation of parametric eigenvalue problems is presented. We motivate our study with the analysis of a POD reduced order model for a simple one dimensional example. In particular, we introduce a new…

This paper focuses on the study of Sturm-Liouville eigenvalue problems. In the classical Chebyshev collocation method, the Sturm-Liouville problem is discretized to a generalized eigenvalue problem where the functions represent interpolants…

Numerical Analysis · Mathematics 2023-05-09 Sameh Gana

The inherently homogeneous stationary-state and time-dependent Schroedinger equations are often recast into inhomogeneous form in order to resolve their solution nonuniqueness. The inhomogeneous term can impose an initial condition or, for…

General Physics · Physics 2013-01-09 Steven Kenneth Kauffmann

A detailed exposition of highly efficient and accurate method for the propagation of the time-dependent Schr\"odinger equation is presented. The method is readily generalized to solve an arbitrary set of ODE's. The propagation is based on a…

Quantum Physics · Physics 2017-05-12 Ido Schaefer , Hillel Tal-Ezer , Ronnie Kosloff