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The Nystr\"om method for the numerical solution of Fredholm integral equations of the second kind is generalized by decoupling the set of solution nodes from the set of quadrature nodes. The accuracy and efficiency of the new method is…

Numerical Analysis · Mathematics 2025-10-21 Bruno Degli Esposti , Alessandra Sestini

This paper examines inverse Cauchy problems that are governed by a kind of elliptic partial differential equation. The inverse problems involve recovering the missing data on an inaccessible boundary from the measured data on an accessible…

Numerical Analysis · Mathematics 2023-12-01 Rongfang Gong , Min Wang , Qin Huang , Ye Zhang

We extend the notion of some energy-type expressions based on two sets, developed in the abstract potential theory. We also give the discretized version of the quantities defined, similar to Chebyshev constant. This extension allows to…

Optimization and Control · Mathematics 2016-11-10 Á. P. Horváth

We consider a class of Fuchsian equations that, for instance, describes the evolution of compressible fluid flows on a cosmological spacetime. Using the method of lines, we introduce a numerical algorithm for the singular initial value…

General Relativity and Quantum Cosmology · Physics 2021-03-17 Florian Beyer , Philippe G. LeFloch

Despite the successful enhancement to the Harrow-Hassidim-Lloyd algorithm by Childs et al., who introduced the Fourier approach leveraging linear combinations of unitary operators, our research has identified non-trivial redundancies within…

Quantum Physics · Physics 2024-05-13 Rui-Bin Xu , Zhu-Jun Zheng , Zheng Zheng

The quasilinearization method (QLM) of solving nonlinear differential equations is applied to the quantum mechanics by casting the Schr\"{o}dinger equation in the nonlinear Riccati form. The method, whose mathematical basis in physics was…

Computational Physics · Physics 2007-05-23 R. Krivec , V. B. Mandelzweig

We present a fully pseudo-spectral scheme to solve axisymmetric hyperbolic equations of second order. With the Chebyshev polynomials as basis functions, the numerical grid is based on the Lobbato (for two spatial directions) and Radau (for…

Computational Physics · Physics 2016-07-28 Rodrigo P. Macedo , Marcus Ansorg

In this paper, the numerical solution of the singular-perturbation Cauchy problem by Runge-Kutta methods on the Shishkin grid is discussed. Numerical solutions of the observed problem were obtained using two explicit and one implicit…

Numerical Analysis · Mathematics 2023-06-21 Vesna Divković , Laura Lukić , Elvir Memić , Samir Karasuljić

The one-dimensional stationary quantum Vlasov equation is analyzed using the energy as one of the dynamical variables, similarly as in the solution of the Vlasov-Poisson system by means of the Bernstein-Greene-Kruskal method. In the…

Quantum Physics · Physics 2021-02-22 Fernando Haas

We propose a novel numerical algorithm for computing the electronic structure related eigenvalue problem of incommensurate systems. Unlike the conventional practice that approximates the system by a large commensurate supercell, our…

Numerical Analysis · Mathematics 2019-03-27 Yuzhi Zhou , Huajie Chen , Aihui Zhou

Harmonic Balance is one of the most popular methods for computing periodic solutions of nonlinear dynamical systems. In this work, we address two of its major shortcomings: First, we investigate to what extent the computational burden of…

Dynamical Systems · Mathematics 2023-03-30 Lukas Woiwode , Malte Krack

In this paper, a novel adaptive finite element method is proposed to solve the Kohn-Sham equation based on the moving mesh (nonnested mesh) adaptive technique and the augmented subspace method. Different from the classical self-consistent…

Numerical Analysis · Mathematics 2024-05-01 Guanghui Hu , Hehu Xie , Fei Xu , Gang Zhao

The finite element method (FEM) is a cornerstone numerical technique for solving partial differential equations (PDEs). Here, we present $\textbf{Qu-FEM}$, a fault-tolerant era quantum algorithm for the finite element method. In contrast to…

Quantum Physics · Physics 2025-10-22 Ahmad M. Alkadri , Tyler D. Kharazi , K. Birgitta Whaley , Kranthi K. Mandadapu

Finite-sum optimization has wide applications in machine learning, covering important problems such as support vector machines, regression, etc. In this paper, we initiate the study of solving finite-sum optimization problems by quantum…

Quantum Physics · Physics 2024-06-06 Yexin Zhang , Chenyi Zhang , Cong Fang , Liwei Wang , Tongyang Li

A global approximation method of Nystr\"om type is explored for the numerical solution of a class of nonlinear integral equations of the second kind. The cases of smooth and weakly singular kernels are both considered. In the first…

Numerical Analysis · Mathematics 2024-07-16 Luisa Fermo , Anna Lucia Laguardia , Concetta Laurita , Maria Grazia Russo

This paper is concerned with the direct and inverse acoustic or electromagnetic scattering problems by a locally perturbed, perfectly reflecting, infinite plane (which is called a locally rough surface in this paper). We propose a novel…

Analysis of PDEs · Mathematics 2013-02-04 Haiwen Zhang , Bo Zhang

We present a multigrid algorithm for self consistent solution of the Kohn-Sham equations in real space. The entire problem is discretized on a real space mesh with a high order finite difference representation. The resulting self consistent…

Materials Science · Physics 2009-10-31 Jian Wang , Thomas L. Beck

We present a highly accurate method for solving single-active-electron (SAE) atomic eigenset in momentum space. The trouble of Coulomb kernel singularity is bypassed with numerical quadrature, which is simple but effective. The complicated…

Quantum Physics · Physics 2017-06-20 Shih-Da Jheng , Tsin-Fu Jiang

In this paper, a new deep-learning architecture for solving the non-linear Falkner-Skan equation is proposed. Using Legendre and Chebyshev neural blocks, this approach shows how orthogonal polynomials can be used in neural networks to…

Machine Learning · Computer Science 2023-08-08 Alireza Afzal Aghaei , Kourosh Parand , Ali Nikkhah , Shakila Jaberi

When a probe qubit is coupled to a quantum register that represents a physical system, the probe qubit will exhibit a dynamical response only when it is resonant with a transition in the system. Using this principle, we propose a quantum…

Quantum Physics · Physics 2014-02-19 Hefeng Wang , Heng Fan , Fuli Li