{"title":"L((theta ))-stable peer methods with reused stages for advection–diffusion-reaction problems","authors":"Giovanni Pagano, Luis Rández","doi":"10.1007/s10444-026-10315-6","DOIUrl":"10.1007/s10444-026-10315-6","url":null,"abstract":"<div><p>This paper addresses the efficient numerical solution of large and stiff initial value problems (IVPs) arising from the space discretization of systems of nonlinear advection–diffusion-reaction partial differential equations (PDEs). To this end, we introduce a new family of linearly implicit two-step peer methods that leverage specialized preconditioners and exploit the reuse of previously computed stages. The proposed methods are constructed to ensure strong stability properties, specifically, L-stability or L(<span>(theta )</span>)-stability with <span>(theta )</span> approaching 90<span>(^{circ })</span>, while maintaining low error constants. Compared to recently developed linearly implicit peer schemes, the new methods significantly reduce both the number of required function evaluations and linear systems to solve at each time step, also resulting in notably diminished error constants. Numerical experiments on nonlinear advection–diffusion-reaction problems testify to the efficiency of the new methods and confirm their accuracy and stability properties.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10444-026-10315-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ying Sun, Kang-Ya Lu, Zong-Han Li, Jun-Heng Niu, Yu-Fan Cao
{"title":"Spectral analysis of the banded preconditioning with adjustable shift compensation for solving two-dimensional Riesz space-fractional diffusion equations","authors":"Ying Sun, Kang-Ya Lu, Zong-Han Li, Jun-Heng Niu, Yu-Fan Cao","doi":"10.1007/s10444-026-10312-9","DOIUrl":"10.1007/s10444-026-10312-9","url":null,"abstract":"<div><p>According to the structure of the discrete linear system derived from the considered two-dimensional Riesz space-fractional diffusion equations, the <i>banded preconditioner with adjustable shift compensation</i> (<b>BASC preconditioner</b>) is constructed to accelerate the convergence rate of the Krylov subspace iteration methods by compensating the banded truncation of the coefficient matrix with a parameterized shift matrix. When the parameter is 1, the BASC preconditioner is exactly the existing <i>banded preconditioner with shift compensation</i> (<b>BSC preconditioner</b>). In addition, by selecting an appropriate parameter close to 1, the BASC preconditioner can outperform the BSC preconditioner or achieve comparable performance, which can be confirmed through asymptotic singular value or eigenvalue analysis as well as numerical experiments.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147938762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A locally conservative enriched virtual element method for elliptic problems","authors":"Xinyu Zhao, Hongxing Rui, Gang Wang","doi":"10.1007/s10444-026-10308-5","DOIUrl":"10.1007/s10444-026-10308-5","url":null,"abstract":"<div><p>In this paper, we present a locally conservative numerical method to solve the general elliptic problems on polygonal or polyhedral meshes. The approximation space of the method is based on enriching that of the virtual element method with elementwise constant functions. For the formulation of the new method, we use the thoughts of the virtual element method to modify the schemes of the enriched Galerkin method. The proposed method has a slightly larger number of degrees of freedom than that of the virtual element method but can preserve the locally conservative property and deal with complicated element geometries. We show the solvability and local conservation of the method and prove the optimal convergence rate of numerical solutions. We can implement the new method only with some slight modifications on the existing code. We also provide some numerical examples to illustrate the optimal convergence rate of the new method and advantages of this method than discontinuous Galerkin method and virtual element method.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147938763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A variable time-step IMEX BDF2 scheme for the incompressible MHD system","authors":"Qianqian Ding, Yifan Luo, Shipeng Mao","doi":"10.1007/s10444-026-10311-w","DOIUrl":"10.1007/s10444-026-10311-w","url":null,"abstract":"<div><p>In this article, we propose and analyze a fully discrete implicit-explicit (IMEX) variable time-step scheme for the incompressible magnetohydrodynamic (MHD) system, in which nonlinear terms are treated fully explicitly while linear terms are handled implicitly. The method combines the variable time-step second-order backward differentiation formula (BDF2) for the temporal with the spatial discretization facilitated by the Taylor-Hood finite element method. Under a mild restriction <span>(0<r_k<r_{max }approx 4.8645)</span> on the ratio of adjacent time steps <span>(r_k)</span>, we derive rigorous local optimal <span>(H^1)</span>-error estimates for both velocity and magnetic induction in the three-dimensional MHD system. The key points in our analysis include the construction and a modified discrete Gr<span>(ddot{text {o}})</span>nwall’s inequality specifically tailored to the MHD system, together with the establishment of the unconditional stability of the numerical solutions. Finally, numerical experiments are performed to validate the theoretical findings.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A discretization theory of meshfree collocation for nonlinear systems of partial differential equations","authors":"Zhiyong Liu, Qiuyan Xu","doi":"10.1007/s10444-026-10310-x","DOIUrl":"10.1007/s10444-026-10310-x","url":null,"abstract":"<div><p>This paper extends for the first time B<span>(ddot{text {o}})</span>hmer/Schaback’s nonlinear discretization theory (J. Comput. Appl. Math., 254\u0000(2013), pp. 204–219) to nonlinear systems of partial differential equations. A direct collocation method is used to solve the coupled nonlinear systems. There are no restrictions on the nonlinear operators; in particular, there is no ellipticity, compactness, or self-adjointness assumed. The trial spaces might include a large class of finite-dimensional approximation spaces such as radial basis functions spaces, spline functions spaces, local Lagrange functions spaces, spectral techniques, and finite element spaces. A general framework for proving the convergence of collocation methods for solving well-posed nonlinear operator equations is presented. The theoretical results cover error bounds and convergence rates. In order to show how the general theoretical framework can be set to work, we take the meshfree method for solving the Navier–Stokes equations as an illustration and derive specific convergence rates in Sobolev spaces. Several numerical examples are provided to deal with numerical efficiency.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ludovico Bruni Bruno, Francesco Dell’Accio, Wolfgang Erb, Federico Nudo
{"title":"Bivariate polynomial histopolation techniques on Padua, Fekete, and Leja triangles","authors":"Ludovico Bruni Bruno, Francesco Dell’Accio, Wolfgang Erb, Federico Nudo","doi":"10.1007/s10444-026-10309-4","DOIUrl":"10.1007/s10444-026-10309-4","url":null,"abstract":"<div><p>This paper explores the reconstruction of a real-valued function <i>f</i> defined over a domain <span>(varOmega subset mathbb {R}^2)</span> using bivariate polynomials that satisfy triangular histopolation conditions. More precisely, we assume that only the averages of <i>f</i> over a given triangulation <span>(mathcal {T}_N)</span> of <span>(varOmega )</span> are available and seek a bivariate polynomial that approximates <i>f</i> using a histopolation approach, potentially flanked by an additional regression technique. This methodology relies on the selection of a subset of triangles <span>(mathcal {T}_M subset mathcal {T}_N)</span> for histopolation, ensuring both the solvability and the well-conditioning of the problem. The remaining triangles can potentially be used to enhance the accuracy of the polynomial approximation through a simultaneous regression. We will introduce histopolation and combined histopolation-regression methods using the Padua points, discrete Leja sequences, and approximate Fekete nodes. The proposed algorithms are implemented and evaluated through numerical experiments that demonstrate their effectiveness in function approximation.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10444-026-10309-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new magnetic-coupled binary phase-field crystal model and its efficient fully discrete decoupled energy-stable scheme","authors":"Hengrui Xu, Kejia Pan, Xiaofeng Yang","doi":"10.1007/s10444-026-10313-8","DOIUrl":"10.1007/s10444-026-10313-8","url":null,"abstract":"<div><p>Despite extensive research on ferromagnetic materials and binary alloys, the interplay between magnetic fields and binary microstructure formation has not yet been systematically modeled within the phase-field crystal (PFC) framework. In this work, we propose a novel magnetic-coupled binary PFC model which, to the best of our knowledge, is the first to integrate ferromagnetic ordering and binary atomic density evolution within a unified formulation. The resulting system consists of three strongly coupled and highly nonlinear partial differential equations: two mass-conserved Allen–Cahn type equations for the binary density fields, and a third Allen-Cahn type equation governing the magnetization field dynamics, derived via a Ginzburg–Landau approach. To solve this challenging system efficiently, we further develop a fully discrete scheme that combines the Invariant Energy Quadratization (IEQ) and Zero-Energy-Contribution (ZEC) approaches for time discretization with a Fourier spectral method for spatial discretization. The proposed scheme is linear, fully decoupled, unconditionally energy stable, and second-order accurate in time, enabling robust and efficient simulation of magneto-structural dynamics. Extensive two- and three-dimensional numerical experiments demonstrate the method’s capability to capture magnetically driven phenomena such as crystal growth and phase transitions. This work not only establishes a new theoretical framework for modeling magnetic field-coupled binary systems but also provides an effective computational tool for simulating complex ferromagnetic material behavior.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10444-026-10313-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Which transmission condition is the best in optimized Schwarz waveform relaxation for viscoelastic equation: Robin or characteristic?","authors":"Fu Li, Yingxiang Xu","doi":"10.1007/s10444-026-10305-8","DOIUrl":"10.1007/s10444-026-10305-8","url":null,"abstract":"<div><p>The viscoelastic equation introduces a viscoelastic damping term in the classical wave equation, thus exhibiting properties of parabolic systems accompanied by hyperbolic properties. On the other hand, it is well known that for parabolic systems, when solved using the optimized Schwarz waveform relaxation (OSWR) method, Robin transmission condition is preferred; however, the characteristic transmission condition is good for hyperbolic systems. In this paper, we investigate what transmission condition should be applied according to different strengths of damping. The results show that, in the OSWR algorithm, for weak damping the characteristic transmission condition is preferred, while for strong damping one should use Robin instead, as anticipated. It is also observed that the convergence depends on the relationship between the temporal and spatial mesh sizes applied, which shows that overlap may not accelerate the convergence. In addition, we find numerically that a mix of both transmission conditions can only improve the convergence for strong damping, and it remains an interesting problem to look for transmission conditions that are more robust in the damping strength.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Well-posedness for an improved time-fractional reaction-diffusion systems","authors":"Ziad Zaabouli, Lekbir Afraites, Aissam Hadri, Amine Laghrib","doi":"10.1007/s10444-026-10307-6","DOIUrl":"10.1007/s10444-026-10307-6","url":null,"abstract":"<div><p>In this article, we establish the existence and uniqueness of a novel mathematical model aimed at image denoising. Our model integrates the fractional Laplacian operator, inspired by the Weickert filter, and employs the time Caputo fractional derivative. Through a rigorous analysis utilizing the <span>(H^{-1})</span> norm decomposition strategy, we present a system of coupled partial differential equations governing the evolution of a denoised image (<i>u</i>) and an associated residual (<i>v</i>) in space and time. Through this exploration, we aim to advance understanding and applications of time-fractional models in addressing challenges in image denoising and related fields.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stabilized gradient flow schemes of phase field model for shape and topology optimization in diffusion","authors":"Jiajie Li, Hui Yang, Shengfeng Zhu","doi":"10.1007/s10444-026-10303-w","DOIUrl":"10.1007/s10444-026-10303-w","url":null,"abstract":"<div><p>Shape and topology optimization constrained by a diffusion equation is modeled by a phase field method. Stabilized gradient flow schemes are proposed to solve the optimal control problems. By addressing the difficulty associated with extra adjoint variables, we derive the unconditional energy stability for the gradient flow using the backward Euler scheme. Moreover, the conditional energy stability of the gradient flow scheme in modified energy using a second-order backward difference formula is demonstrated. Numerical experiments for heat compliance, mean temperature control, and geometric inverse problem are presented to verify the effectiveness of the proposed methods.</p></div>","PeriodicalId":50869,"journal":{"name":"Advances in Computational Mathematics","volume":"52 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147738729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}