{"title":"A new error analysis of an explicit skeletal discontinuous Galerkin scheme for time-dependent Maxwell equations","authors":"Achyuta Ranjan Dutta Mohapatra, Bhupen Deka","doi":"10.1016/j.apnum.2025.05.011","DOIUrl":"10.1016/j.apnum.2025.05.011","url":null,"abstract":"<div><div>This article focuses on the convergence analysis of second-order time-dependent Maxwell equations in conducting and non-conducting media. Firstly, the spatial discretization is made using a skeletal discontinuous Galerkin method, and then some essential tools are established to deduce the stability and error estimates. Under suitable regularity assumptions on initial data, stability and optimal convergence of the error are proved for the semi-discrete problem in a discretely defined <span><math><mi>H</mi><mtext>(curl)</mtext></math></span>-norm. Next, temporal discretization is applied to the semi-discrete system by using the explicit Leap-frog schemes and optimal error bounds <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>τ</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msup><mrow><mi>h</mi></mrow><mrow><mi>k</mi></mrow></msup><mo>)</mo></math></span>, <span><math><mi>k</mi><mo>≥</mo><mn>1</mn></math></span> is the degree of polynomial approximation, are achieved in the discrete energy norm. Finally, computational experiments are performed to validate the theoretical conclusions. Error analysis of explicit fully discrete schemes in polygonal/polyhedral meshes for the second-order Maxwell equations in a conducting media is missing in the literature, and we intend to fill this gap in the current article.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"217 ","pages":"Pages 18-42"},"PeriodicalIF":2.2,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Split-step θ-method for stochastic pantograph differential equations: Convergence and mean-square stability analysis","authors":"Fathalla A. Rihan, K. Udhayakumar","doi":"10.1016/j.apnum.2025.05.010","DOIUrl":"10.1016/j.apnum.2025.05.010","url":null,"abstract":"<div><div>This paper introduces a <em>split-step θ-method</em> (SS<em>θ</em>-method) with variable step sizes for solving stochastic pantograph delay differential equations (SPDDEs). We establish the mean-square convergence of the proposed SS<em>θ</em>-method and show that it achieves a strong convergence order of order 1/2. Under certain assumptions, we prove that the SS<em>θ</em>-method is exponentially mean-square stable for <span><math><mi>θ</mi><mo>≥</mo><mn>0.5</mn></math></span>. Additionally, we analyze the asymptotic mean-square stability of the SS<em>θ</em>-method under a stronger assumption. Finally, numerical examples illustrate the effectiveness of the proposed methods.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"217 ","pages":"Pages 1-17"},"PeriodicalIF":2.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-order numerical solution for solving multi-dimensional Schrödinger-Poisson equation","authors":"Maedeh Nemati, Mostafa Abbaszadeh, Mehdi Dehghan","doi":"10.1016/j.apnum.2025.05.004","DOIUrl":"10.1016/j.apnum.2025.05.004","url":null,"abstract":"<div><div>This paper explores the numerical solution of the Schrödinger-Poisson equation in one, two, and three dimensions, which has significant applications in quantum mechanics, cosmology, Bose-Einstein condensates, and nonlinear optics. To address the nonlinear aspects of the problem, we employ the split-step method, which decomposes the equation into linear and nonlinear components. The linear part is discretized using the compact finite difference (CFD) method, while the nonlinear component is solved exactly. For temporal discretization, we utilize the Crank-Nicolson method across all dimensions, achieving a second-order convergence rate of <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>τ</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span>. Spatial discretization is carried out using a CFD scheme, ensuring a fourth-order convergence rate of <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>h</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>)</mo></math></span>. In the case of two- and three-dimensional Schrödinger equations, the alternating direction implicit (ADI) method is applied. We establish that the proposed numerical schemes are convergent, unconditionally stable, and maintain the conservation of mass and energy at the discrete level. Numerical experiments in one, two, and three dimensions validate the effectiveness of our approach. Specifically, we compare the split-step CFD scheme with alternative methods, and for higher-dimensional cases, we evaluate the ADI-split-step CFD scheme against the standard split-step CFD method. The results demonstrate that the proposed methods significantly reduce computational time while maintaining accuracy.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"217 ","pages":"Pages 43-72"},"PeriodicalIF":2.2,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An energy stable and well-balanced scheme for the Ripa system","authors":"K.R. Arun , R. Ghorai","doi":"10.1016/j.apnum.2025.05.008","DOIUrl":"10.1016/j.apnum.2025.05.008","url":null,"abstract":"<div><div>We design and analyse an energy-stable, structure-preserving, and well-balanced scheme for the Ripa system of shallow water equations. The energy stability of the numerical solutions is achieved by introducing appropriate stabilisation terms in the discretisation of the convective fluxes of mass and momentum, the pressure gradient, and the topography source term. The careful selection of the interface values for the water height and temperature ensures the scheme's well-balancing property for three physically relevant hydrostatic steady states. The scheme, which is explicit in time and finite volume in space, preserves the positivity of both the water height and the temperature, and it is weakly consistent with the continuous model equations in the sense of Lax-Wendroff. Additionally, a suitable modification of the source term discretisation and timestep criterion allows the scheme to handle wet/dry fronts in equilibrium. The results of extensive numerical case studies on benchmark test problems confirm the theoretical findings.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 187-209"},"PeriodicalIF":2.2,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-order and mass-conservative regularized implicit-explicit relaxation Runge-Kutta methods for the low regularity Schrödinger equations","authors":"Jingye Yan , Hong Zhang , Yabing Wei , Xu Qian","doi":"10.1016/j.apnum.2025.05.009","DOIUrl":"10.1016/j.apnum.2025.05.009","url":null,"abstract":"<div><div>The non-differentiability of the singular nonlinearities (<span><math><mi>f</mi><mo>=</mo><mi>ln</mi><mo></mo><mo>|</mo><mi>u</mi><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup></math></span> and <span><math><mi>f</mi><mo>=</mo><mo>|</mo><mi>u</mi><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn><mi>α</mi></mrow></msup><mo>,</mo><mspace></mspace><mi>α</mi><mo><</mo><mn>0</mn></math></span>) at <span><math><mi>u</mi><mo>=</mo><mn>0</mn></math></span> brings significant challenges in designing accurate and efficient numerical schemes for the low regularity Schrödinger equations (LorSE). In order to address the singularity, we propose an energy regularization for the LorSE. For the regularized models, we apply Implicit-explicit Relaxation Runge-Kutta methods which are linearly implicit, high order and mass-conserving for temporal discretization, in conjunction with the Fourier pseudo-spectral method in space. Ultimately, numerical results are presented to validate the efficiency of the proposed methods.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 210-221"},"PeriodicalIF":2.2,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144139588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rui M.P. Almeida , José C.M. Duque , Jorge Ferreira , Willian S. Panni
{"title":"Numerical analysis for an evolution equation with the p-biharmonic operator","authors":"Rui M.P. Almeida , José C.M. Duque , Jorge Ferreira , Willian S. Panni","doi":"10.1016/j.apnum.2025.05.006","DOIUrl":"10.1016/j.apnum.2025.05.006","url":null,"abstract":"<div><div>In this paper, we consider a parabolic equation with the <em>p</em>-biharmonic operator, where <span><math><mi>p</mi><mo>></mo><mn>1</mn></math></span>. By employing a suitable change of variable, we transform the fourth-order nonlinear parabolic problem into a system of two second-order differential equations. We investigate the properties of the discretized solution in spatial and temporal variables. Using the Brouwer fixed point theorem we prove the existence of the discretized solution. Through classical functional analysis techniques we demonstrate the uniqueness and a priori estimates of the discretized solution. We establish the order of convergence in space and time, we establish the relationship between the temporal variable and the spatial variable, ensuring the existence of the convergence order. Additionally, we highlight that the change in variable carried out is extremely advantageous, as it allows us to obtain the order of convergence for the solution and its higher order derivatives using only lower-degree polynomials. Finally, using the finite element method with Lagrange basis, we implement the computational codes in Matlab software, considering the one and two-dimensional cases. We present three examples to illustrate and validate the theory.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 164-186"},"PeriodicalIF":2.2,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sinc approximation method for solving system of singularly perturbed parabolic convection-diffusion equations","authors":"N. Barzehkar, A. Barati, R. Jalilian","doi":"10.1016/j.apnum.2025.05.005","DOIUrl":"10.1016/j.apnum.2025.05.005","url":null,"abstract":"<div><div>In this paper, the Sinc-collocation method is used to solve singularly perturbed parabolic convection-diffusion system. The convergence analysis of the proposed method is discussed, it is shown that the convergence of the method is at an exponential rate in space dimension. Finally, some numerical results are given to validate the theoretical results. Also, the obtained results show the accuracy and efficiency of the method compared with other methods.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 127-139"},"PeriodicalIF":2.2,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rongfang Gong , Xiaohui Liu , Catharine W.K. Lo , Gaocheng Yue
{"title":"A study of Cauchy problem of the Helmholtz equation based on a relaxation model: Regularization and analysis","authors":"Rongfang Gong , Xiaohui Liu , Catharine W.K. Lo , Gaocheng Yue","doi":"10.1016/j.apnum.2025.05.007","DOIUrl":"10.1016/j.apnum.2025.05.007","url":null,"abstract":"<div><div>In this paper, we consider a Cauchy problem of the Helmholtz equation of recovering both missing voltage and current on inaccessible boundary from Cauchy data measured on the remaining accessible boundary. With an introduction of a relaxation parameter, the Dirichlet boundary conditions are approximated by two Robin ones. Associated with two mixed boundary value problems, a regularized Kohn-Vogelius formulation is proposed. Compared to the existing work, weaker regularity is required on the Dirichlet data and no Dirichlet BVPs needs to be solved. This makes the proposed model simpler and more efficient in computation. The well-posedness analysis about the relaxation model and error estimates of the corresponding inverse problem are obtained. A series of theoretical results are established for the new reconstruction model. Several numerical examples are provided to show feasibility and effectiveness of the proposed method.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 140-163"},"PeriodicalIF":2.2,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A second-order semi-implicit spectral deferred correction scheme for Cahn-Hilliard-Navier-Stokes equation","authors":"Xin Liu , Dandan Xue , Shuaichao Pei , Hong Yang","doi":"10.1016/j.apnum.2025.05.003","DOIUrl":"10.1016/j.apnum.2025.05.003","url":null,"abstract":"<div><div>In this paper, a second-order and energy stable numerical scheme is developed to solve the Cahn-Hilliard-Navier-Stokes phase field model with matching density. This scheme is based on the second-order semi-implicit spectral deferred correction method and the energy stable first-order convex splitting approach. A fully discretized scheme with finite elements for the spatial discretization is developed to solve this coupled system. The energy stability of our scheme is theoretically proven, and its convergence is verified numerically. Numerical experiments are conducted to demonstrate the stability and reliability of the proposed scheme.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 39-55"},"PeriodicalIF":2.2,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143946841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On greedy randomized coordinate updating iteration methods for solving symmetric eigenvalue problems","authors":"Zhong-Zhi Bai","doi":"10.1016/j.apnum.2025.04.010","DOIUrl":"10.1016/j.apnum.2025.04.010","url":null,"abstract":"<div><div>In order to compute the smallest eigenvalue and its corresponding eigenvector of a large-scale, real, and symmetric matrix, we propose a class of greedy randomized coordinate updating iteration methods based on the principle that the indices of larger entries in absolute value of the current residual are selected with a higher probability and, with respect to this index set, the next iterate is updated from the current iterate along with the selected coordinate such that the corresponding entry of the residual is annihilated, resulting in fast convergence rates of the proposed iteration methods. Under appropriate conditions, we prove the convergence of both sequences of the Rayleigh-quotients and the acute angles between the iterates and the eigenvector in terms of the expectation. By numerical experiments, we show that this class of greedy randomized coordinate updating iteration methods are advantageous over the parameterized power method and the coordinate descent method in both iteration counts and computing times. Moreover, with theoretical analysis and computational performance, we confirm that the convergence property of this class of iteration methods can be improved significantly by suitably choosing the arbitrary nonnegative parameter involved in the greedy probability criterion.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"216 ","pages":"Pages 76-97"},"PeriodicalIF":2.2,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}