{"title":"A new hybrid trigonometric WENO scheme for hyperbolic conservation laws and highly oscillatory problems","authors":"","doi":"10.1016/j.aml.2024.109339","DOIUrl":"10.1016/j.aml.2024.109339","url":null,"abstract":"<div><div>In the conventional hybrid WENO scheme, the computation of extremum points of high-order polynomials is required, which poses challenges when extending this methodology to the hybrid trigonometric WENO (TWENO) scheme due to the difficulties in determining the extremum points of high-order trigonometric polynomials. In this paper, we propose a novel hybrid strategy that circumvents the necessity of finding extremum points of high-degree polynomials, requiring only the extremum points of three lower-order polynomials. Based on this hybrid strategy, two hybrid TWENO schemes are designed, both of which significantly improve the numerical simulation performance of the TWENO scheme while saving approximately 80% of the computation time.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532518","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":"Adaptive-coefficient finite difference frequency domain method for time fractional diffusive-viscous wave equation arising in geophysics","authors":"","doi":"10.1016/j.aml.2024.109337","DOIUrl":"10.1016/j.aml.2024.109337","url":null,"abstract":"<div><div>The diffusive-viscous wave (DVW) equation is a widely used model to describe frequency dependent attenuation of seismic wave in fluid-saturated porous medium. In this paper taking power law frequency dependent attenuation into account, we first introduce a modified DVW equation (time fractional DVW equation) in which the first order temporal derivative of viscous term is replaced with a fractional order temporal derivative. In consideration of that most of the existing numerical simulations for seismic wave equations are based on time domain methods and truncation with some specific boundary conditions, we incorporate the absorbing boundary condition as complex-frequency-shifted (CFS) perfectly matched layer (PML) into the time fractional DVW equation, and then develop an adaptive-coefficient (AC) finite difference frequency domain (FDFD) method for numerical simulation. The corresponding analytical solution for homogeneous time fractional DVW equation is provided for model validation, and the effectiveness of the developed AC FDFD method is verified by some numerical examples including the homogeneous model and the layered model. Numerical results show that AC FDFD method is more accurate than the traditional 2nd-order FDFD method for numerical modeling of time fractional DVW equation with CFS PML absorbing boundary condition, while requiring similar computational costs.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553185","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":"Mass concentration near the boundary for attractive Bose–Einstein condensates in bounded domains","authors":"","doi":"10.1016/j.aml.2024.109338","DOIUrl":"10.1016/j.aml.2024.109338","url":null,"abstract":"<div><div>We are devoted to studying the ground states of trapped attractive Bose–Einstein condensates in a bounded domain <span><math><mrow><mi>Ω</mi><mo>⊂</mo><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span>, which can be described by minimizers of <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-critical constraint Gross–Pitaevskii energy functional. It has been shown that there is a threshold <span><math><mrow><msup><mrow><mi>a</mi></mrow><mrow><mo>∗</mo></mrow></msup><mo>></mo><mn>0</mn></mrow></math></span> such that minimizers exist if and only if the interaction strength <span><math><mi>a</mi></math></span> satisfies <span><math><mrow><mi>a</mi><mo><</mo><msup><mrow><mi>a</mi></mrow><mrow><mo>∗</mo></mrow></msup></mrow></math></span>. In present paper, we prove that when the trapping potential <span><math><mrow><mi>V</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span> attains its flattest global minimum only at the boundary of <span><math><mi>Ω</mi></math></span>, the mass of minimizers must concentrate near the boundary of <span><math><mi>Ω</mi></math></span> as <span><math><mrow><mi>a</mi><mo>↗</mo><msup><mrow><mi>a</mi></mrow><mrow><mo>∗</mo></mrow></msup></mrow></math></span>. This result extends the work of Luo and Zhu (2019).</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532517","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":"Note on the diffusive prey-predator model with variable coefficients and degenerate diffusion","authors":"","doi":"10.1016/j.aml.2024.109335","DOIUrl":"10.1016/j.aml.2024.109335","url":null,"abstract":"<div><div>It is of interest to understand effects of variable coefficients and degenerate diffusion on the longtime behaviors of solutions of reaction diffusion equations. Recently, Yang and Yao (2024) studied a classical prey-predator model and proved that the degradation of the diffusion coefficient of the prey and variable coefficients satisfying the appropriate conditions will not affect dynamical properties. In this note we shall simplify the proof of Yang and Yao (2024) and delete the condition (4).</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532516","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 locking-free virtual element method for 3D linear elasticity problems","authors":"","doi":"10.1016/j.aml.2024.109333","DOIUrl":"10.1016/j.aml.2024.109333","url":null,"abstract":"<div><div>This paper focuses on proposing and analyzing a new locking-free lowest order virtual element method for the linear elasticity problem in three dimensions. A virtual element function on a polyhedron <span><math><mi>K</mi></math></span> is harmonic, while it is continuous piecewise linear corresponding to an auxiliary triangulation on the boundary <span><math><mrow><mi>∂</mi><mi>K</mi></mrow></math></span>. Such construction requires no further three-dimensional partition of <span><math><mi>K</mi></math></span>. Under some reasonable mesh assumptions, we derive the inverse inequality, the norm equivalence and the error estimate of the interpolation operator for the underlying virtual element. Using these results combined with a rigorous analysis, we establish a robust error estimate in <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> norm for the proposed method. Finally, we perform numerical results to demonstrate theoretical findings.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432113","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":"New negative-determination conditions for cubic polynomials with applications to time-varying delay systems","authors":"","doi":"10.1016/j.aml.2024.109336","DOIUrl":"10.1016/j.aml.2024.109336","url":null,"abstract":"<div><div>This paper studies the stability of time delay systems. The Lyapunov-Krasovskii functional (LKF) method is used for our study, in which a novel negative-determination criterion for cubic polynomials is proposed. An improved stability criterion of time delay system is obtained by the new method. The effectiveness of the proposed method is verified by some numerical examples and reduced conservativeness can be obtained.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553183","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":"Dynamics of a non-local intraspecific competition predator–prey model with memory effect","authors":"","doi":"10.1016/j.aml.2024.109334","DOIUrl":"10.1016/j.aml.2024.109334","url":null,"abstract":"<div><div>In the paper, we investigate a diffusive predator–prey model with nonlocal intraspecific prey competition and spatial memory under Neumann boundary conditions. Through stability and bifurcation analysis, we find that the memory-based diffusion coefficient and the spatiotemporal diffusive delay have important effects on the dynamics of the model. By using the spatiotemporal diffusive delay as a bifurcation parameter, the critical values are determined for the stability of the positive constant steady state and the associated Hopf bifurcation. We find that the system may admit no stability switch, one stability switch and multiple stability switches.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428012","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 perturbations for spectrum and singular value decompositions followed by deflation techniques","authors":"","doi":"10.1016/j.aml.2024.109332","DOIUrl":"10.1016/j.aml.2024.109332","url":null,"abstract":"<div><div>The calculation of the dominant eigenvalues of a symmetric matrix <span><math><mi>A</mi></math></span> together with its eigenvectors, followed by the calculation of the deflation of <span><math><mrow><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mi>A</mi><mo>−</mo><mi>ρ</mi><msub><mrow><mi>U</mi></mrow><mrow><mi>k</mi></mrow></msub><msubsup><mrow><mi>U</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>T</mi></mrow></msubsup></mrow></math></span> corresponds to one step of the Wielandt deflation technique, where <span><math><mi>ρ</mi></math></span> is a shift and <span><math><msub><mrow><mi>U</mi></mrow><mrow><mi>k</mi></mrow></msub></math></span> are eigenvectors of <span><math><mi>A</mi></math></span>. In this paper, we investigate how the eigenspace of <span><math><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> changes when <span><math><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> is perturbed to <span><math><mrow><msub><mrow><mover><mrow><mi>A</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mi>A</mi><mo>−</mo><mi>ρ</mi><msub><mrow><mover><mrow><mi>U</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mi>k</mi></mrow></msub><msubsup><mrow><mover><mrow><mi>U</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mi>k</mi></mrow><mrow><mi>T</mi></mrow></msubsup></mrow></math></span>, where <span><math><msub><mrow><mover><mrow><mi>U</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mi>k</mi></mrow></msub></math></span> are approximate eigenvectors of <span><math><mi>A</mi></math></span>. We establish the bounds for the angle of eigenspaces of <span><math><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mover><mrow><mi>A</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mn>1</mn></mrow></msub></math></span> based on the Davis-Kahan theorem. Moreover, in the practical implementation for singular value decomposition, once one or several singular triplets converge to a preset accuracy, they should be deflated by <span><math><mrow><msub><mrow><mi>B</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mi>B</mi><mo>−</mo><mi>γ</mi><msub><mrow><mi>W</mi></mrow><mrow><mi>k</mi></mrow></msub><msubsup><mrow><mi>V</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>H</mi></mrow></msubsup></mrow></math></span> with <span><math><mi>γ</mi></math></span> being a shift, <span><math><msub><mrow><mi>W</mi></mrow><mrow><mi>k</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>k</mi></mrow></msub></math></span> are singular vectors of <span><math><mi>B</mi></math></span>, so that they will not be re-computed. We investigate how the singular subspaces of <span><math><mrow><msub><mrow><mi>B</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mi>B</mi><mo>−</mo><mi>γ</mi><msub><mrow><mi>W</mi></mrow><mrow><mi>k</mi></mrow></msub><msubsup><mrow><mi>V</m","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428011","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":"Localized Fourier collocation method for 2D transient heat conduction problems","authors":"","doi":"10.1016/j.aml.2024.109331","DOIUrl":"10.1016/j.aml.2024.109331","url":null,"abstract":"<div><div>The localized Fourier collocation method (LFCM) is a newly developed meshless approach for solving certain types of partial differential equations (PDEs). The main idea of this method is to break down the problem domain into a series of overlapping small regions, where the solution within each sub-domain is approximated using Fourier series expansions. The rapid convergence and high computational accuracy make the method particularly effective for handing complex geometries and boundary conditions. This paper presents the first application of LFCM to transient heat conduction problems. The Houbolt method is employed for the time discretization. Several benchmark examples with complex geometries and diverse initial/boundary conditions are well-studied to illustrate the flexibility and accuracy of the new method.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428008","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":"Analysis of degenerate p-Laplacian elliptic equations involving Hardy terms: Existence and numbers of solutions","authors":"","doi":"10.1016/j.aml.2024.109330","DOIUrl":"10.1016/j.aml.2024.109330","url":null,"abstract":"<div><div>This article investigates the existence of solutions to quasilinear degenerate elliptic equation with Hardy singular coefficient, in which the weighted function <span><math><mrow><mi>ω</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span> is unbounded (singular), then we cannot use the classical space <span><math><mrow><msubsup><mrow><mi>W</mi></mrow><mrow><mn>0</mn></mrow><mrow><mn>1</mn><mo>,</mo><mi>p</mi></mrow></msubsup><mrow><mo>(</mo><mi>Ω</mi><mo>)</mo></mrow></mrow></math></span>, so we have to find another space <span><math><mrow><msubsup><mrow><mi>W</mi></mrow><mrow><mn>0</mn></mrow><mrow><mn>1</mn><mo>,</mo><mi>p</mi></mrow></msubsup><mrow><mo>(</mo><mi>ω</mi><mo>,</mo><mi>Ω</mi><mo>)</mo></mrow></mrow></math></span> to deal with the difficulties caused by singularities or degeneracies. New criteria for the existence of at least one and at least two generalized solutions are established via variational methods and critical point theorems provided that the nonlinearity satisfies appropriate hypotheses.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428009","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}