Pub Date : 2026-01-11DOI: 10.1016/j.cam.2026.117342
Tanya V. Tafolla , Stéphane Gaudreault , Mayya Tokman
High order exponential integrators require computing linear combination of exponential-like φ-functions of large matrices A times a vector v. Krylov projection methods are the most general and remain an efficient choice for computing the matrix-function-vector-product evaluation when the matrix A is large and unable to be explicitly stored, or when obtaining information about the spectrum is expensive. The Krylov approximation relies on the Gram-Schmidt (GS) orthogonalization procedure to produce the orthonormal basis Vm. In parallel, GS orthogonalization requires global synchronizations for inner products and vector normalization in the orthogonalization process. Reducing the amount of global synchronizations is of paramount importance for the efficiency of a numerical algorithm in a massively parallel setting. We improve the strong scaling properties and parallel efficiency of exponential integrators by addressing the underlying bottleneck in the linear algebra using low-synchronization GS methods. The resulting orthogonalization algorithms have an accuracy comparable to modified Gram-Schmidt yet are better suited for distributed architecture, as only one global communication is required per orthogonalization-step. We present geophysics based numerical experiments and standard examples routinely used to test stiff time integrators, which validate that reducing global communication leads to better parallel scalability and reduced time-to-solution for exponential integrators.
{"title":"Low-synchronization Arnoldi algorithms with application to exponential integrators","authors":"Tanya V. Tafolla , Stéphane Gaudreault , Mayya Tokman","doi":"10.1016/j.cam.2026.117342","DOIUrl":"10.1016/j.cam.2026.117342","url":null,"abstract":"<div><div>High order exponential integrators require computing linear combination of exponential-like φ-functions of large matrices <em>A</em> times a vector <em>v</em>. Krylov projection methods are the most general and remain an efficient choice for computing the matrix-function-vector-product evaluation when the matrix <em>A</em> is large and unable to be explicitly stored, or when obtaining information about the spectrum is expensive. The Krylov approximation relies on the Gram-Schmidt (GS) orthogonalization procedure to produce the orthonormal basis <em>V<sub>m</sub></em>. In parallel, GS orthogonalization requires <em>global synchronizations</em> for inner products and vector normalization in the orthogonalization process. Reducing the amount of global synchronizations is of paramount importance for the efficiency of a numerical algorithm in a massively parallel setting. We improve the strong scaling properties and parallel efficiency of exponential integrators by addressing the underlying bottleneck in the linear algebra using low-synchronization GS methods. The resulting orthogonalization algorithms have an accuracy comparable to modified Gram-Schmidt yet are better suited for distributed architecture, as only one global communication is required per orthogonalization-step. We present geophysics based numerical experiments and standard examples routinely used to test stiff time integrators, which validate that reducing global communication leads to better parallel scalability and reduced time-to-solution for exponential integrators.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117342"},"PeriodicalIF":2.6,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979450","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}
Large-scale quaternion matrix equations face challenges such as high dimensionality and non-commutativity of quaternion multiplication, which often result in high computational complexity and low efficiency with conventional methods. To this end, utilizing generalized Hamilton-real (GHR) calculus, we propose a quaternion random reshuffling (QRR) algorithm for solving large-scale quaternion matrix equations. We also provide a convergence analysis for the QRR algorithm. Numerical experiments show that the QRR algorithm achieves stable convergence performance and faster convergence rates in solving large-scale generalized Sylvester quaternion matrix equations. Thus, the QRR algorithm is expected to provide an efficient and robust solution for solving large-scale quaternion matrix equations.
{"title":"A random reshuffling method for generalized Sylvester quaternion matrix equations","authors":"Qiankun Diao , Yiming Jiang , Jinlan Liu , Dongpo Xu","doi":"10.1016/j.cam.2026.117346","DOIUrl":"10.1016/j.cam.2026.117346","url":null,"abstract":"<div><div>Large-scale quaternion matrix equations face challenges such as high dimensionality and non-commutativity of quaternion multiplication, which often result in high computational complexity and low efficiency with conventional methods. To this end, utilizing generalized Hamilton-real (GHR) calculus, we propose a quaternion random reshuffling (QRR) algorithm for solving large-scale quaternion matrix equations. We also provide a convergence analysis for the QRR algorithm. Numerical experiments show that the QRR algorithm achieves stable convergence performance and faster convergence rates in solving large-scale generalized Sylvester quaternion matrix equations. Thus, the QRR algorithm is expected to provide an efficient and robust solution for solving large-scale quaternion matrix equations.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117346"},"PeriodicalIF":2.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979372","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}
Pub Date : 2026-01-08DOI: 10.1016/j.cam.2026.117345
Jiamin Lu, Liwen Xu, Hao Cheng
In this paper, we investigate an inverse random source problem for the fractional pseudo-parabolic equation, where the source is driven by a fractional Brownian motion (fBm). For the direct problem, we illustrate the existence and uniqueness of the mild solution. For the inverse random source problem, the uniqueness is proved and the instability is characterized. To address this instability, we apply Tikhonov regularization, achieving stable numerical solutions and giving error estimates. Finally, numerical experiments demonstrate the effectiveness of the regularization method.
{"title":"An inverse random source problem for pseudo-parabolic equation of Caputo type with fractional-order Laplacian operator","authors":"Jiamin Lu, Liwen Xu, Hao Cheng","doi":"10.1016/j.cam.2026.117345","DOIUrl":"10.1016/j.cam.2026.117345","url":null,"abstract":"<div><div>In this paper, we investigate an inverse random source problem for the fractional pseudo-parabolic equation, where the source is driven by a fractional Brownian motion (fBm). For the direct problem, we illustrate the existence and uniqueness of the mild solution. For the inverse random source problem, the uniqueness is proved and the instability is characterized. To address this instability, we apply Tikhonov regularization, achieving stable numerical solutions and giving error estimates. Finally, numerical experiments demonstrate the effectiveness of the regularization method.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117345"},"PeriodicalIF":2.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979454","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}
Pub Date : 2026-01-08DOI: 10.1016/j.cam.2026.117344
Wenqi Lu , Hongmei Lin , Heng Lian
Problems involving a low-rank tensor with a Tucker format or a tensor train (TT) format, such as the tensor decomposition or tensor optimization problems, have been frequently studied in the literature. Motivated by the success of randomized algorithms for low-rank matrix decomposition, we develop randomized algorithms for these two tensor formats and present a detailed theoretical analysis of the randomized tensor decomposition as well as on its use in the optimization and regression problem. For the latter, we focus on the nonconvex projected gradient descent algorithm previously used only on the Tucker format, which we also extend to the TT format, where one key step in the computation is performing singular value decomposition of the matricized tensor variable. We provide error bounds both in expectation and bounds with high probability.
{"title":"Randomized tensor decomposition and optimization in the tucker and tensor train formats","authors":"Wenqi Lu , Hongmei Lin , Heng Lian","doi":"10.1016/j.cam.2026.117344","DOIUrl":"10.1016/j.cam.2026.117344","url":null,"abstract":"<div><div>Problems involving a low-rank tensor with a Tucker format or a tensor train (TT) format, such as the tensor decomposition or tensor optimization problems, have been frequently studied in the literature. Motivated by the success of randomized algorithms for low-rank matrix decomposition, we develop randomized algorithms for these two tensor formats and present a detailed theoretical analysis of the randomized tensor decomposition as well as on its use in the optimization and regression problem. For the latter, we focus on the nonconvex projected gradient descent algorithm previously used only on the Tucker format, which we also extend to the TT format, where one key step in the computation is performing singular value decomposition of the matricized tensor variable. We provide error bounds both in expectation and bounds with high probability.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117344"},"PeriodicalIF":2.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979371","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}
Pub Date : 2026-01-08DOI: 10.1016/j.cam.2026.117339
Corentin Bonte, Arne Bouillon, Giovanni Samaey, Karl Meerbergen
Recently, the ParaOpt algorithm was proposed as an extension of the time-parallel Parareal method to optimal control. ParaOpt uses quasi-Newton steps that each require solving a system of matching conditions iteratively. The state-of-the-art parallel preconditioner for linear problems leads to a set of independent smaller systems that are currently hard to solve. We generalize the preconditioner to the nonlinear case and propose a new, fast inversion method for these smaller systems, avoiding disadvantages of the current options with adjusted boundary conditions in the subproblems.
{"title":"Efficient parallel inversion of ParaOpt preconditioners","authors":"Corentin Bonte, Arne Bouillon, Giovanni Samaey, Karl Meerbergen","doi":"10.1016/j.cam.2026.117339","DOIUrl":"10.1016/j.cam.2026.117339","url":null,"abstract":"<div><div>Recently, the ParaOpt algorithm was proposed as an extension of the time-parallel Parareal method to optimal control. ParaOpt uses quasi-Newton steps that each require solving a system of matching conditions iteratively. The state-of-the-art parallel preconditioner for linear problems leads to a set of independent smaller systems that are currently hard to solve. We generalize the preconditioner to the nonlinear case and propose a new, fast inversion method for these smaller systems, avoiding disadvantages of the current options with adjusted boundary conditions in the subproblems.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117339"},"PeriodicalIF":2.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979378","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}
Battery cycling, both in application and Research and Development (R&D) environments, generates a wealth of information that often remains underexploited. Thus, potentially valuable information contained in electrical transients is frequently overlooked. In this framework, battery response modelling and model-based data analysis provide powerful tools to extract valuable information on battery status, its evolution and its correlation with functional performance. In this scenario, recently, we have developed a PDE model of battery potential response controlled by electrode shape changes in the BCs for high energy-density metal electrodes. In this work, on the basis of this model, we carry out a classification of the potential transient types, to enable a systematic comparison between model solution and experimental time-series. For transient shape classification purposes, we found that cluster analysis can play a key role in discovering hidden structures within the data. Specifically, in this paper, we apply the K-Means clustering algorithm to classify voltage profiles obtained as numerical solutions of the PDE model for the case of symmetric Li/Li cells. We introduce a weighted discrete Sobolev distance that allows us to spot changes in the shape of the voltage profiles, such as formation of peaks, valleys and concavities, that standard metrics such as the norm fail to capture. As an application, we consider a selection of experimental galvanostatic discharge-charge potential time-series to classify their shape in terms of cluster centroids. Moreover, we show that the new clustering algorithm can provide a segmentation of the parameter space of the PDE model. This partitioning is useful to link the experimental profiles to specific parameter ranges. In particular, we report an example to validate the fitting results of a recent publication of ours obtained via a Deep Learning approach for the same measured profiles.
{"title":"Shape classification of battery cycling profiles via K-Means clustering based on a Sobolev distance","authors":"Maria Grazia Quarta , Ivonne Sgura , Massimo Frittelli , Raquel Barreira , Benedetto Bozzini","doi":"10.1016/j.cam.2026.117365","DOIUrl":"10.1016/j.cam.2026.117365","url":null,"abstract":"<div><div>Battery cycling, both in application and Research and Development (R&D) environments, generates a wealth of information that often remains underexploited. Thus, potentially valuable information contained in electrical transients is frequently overlooked. In this framework, battery response modelling and model-based data analysis provide powerful tools to extract valuable information on battery status, its evolution and its correlation with functional performance. In this scenario, recently, we have developed a PDE model of battery potential response controlled by electrode shape changes in the BCs for high energy-density metal electrodes. In this work, on the basis of this model, we carry out a classification of the potential transient types, to enable a systematic comparison between model solution and experimental time-series. For transient shape classification purposes, we found that cluster analysis can play a key role in discovering hidden structures within the data. Specifically, in this paper, we apply the K-Means clustering algorithm to classify voltage profiles obtained as numerical solutions of the PDE model for the case of symmetric Li/Li cells. We introduce a <em>weighted discrete Sobolev distance</em> that allows us to spot changes in the shape of the voltage profiles, such as formation of peaks, valleys and concavities, that standard metrics such as the <span><math><msup><mrow><mi>L</mi></mrow><mn>2</mn></msup></math></span> norm fail to capture. As an application, we consider a selection of experimental galvanostatic discharge-charge potential time-series to classify their shape in terms of cluster centroids. Moreover, we show that the new clustering algorithm can provide a segmentation of the parameter space of the PDE model. This partitioning is useful to link the experimental profiles to specific parameter ranges. In particular, we report an example to validate the fitting results of a recent publication of ours obtained via a Deep Learning approach for the same measured profiles.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"483 ","pages":"Article 117365"},"PeriodicalIF":2.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039581","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}
This research is about a nonlocal dispersal host-pathogen model with Neumann boundary conditions. The nonlocal dispersion operator lacks compactness, which generates an additional challenge in showing the existence of a global compact attractor, and then the stability of the steady states. Therefore, we study the asymptotic stability of the positive steady states, where we show that depends on R0. For R0 < 1, we prove the global asymptotic stability of the pathogen-free steady state, whereas for R0 > 1, we demonstrate the model’s uniform persistence and the existence of a positive steady state. Moreover, we establish the global behavior of the positive steady state for two cases: (i) the spatially homogeneous case, with both dispersal coefficients are not a zero, (ii) the spatially heterogeneous case, with one of the dispersion rate is a zero. Finally, the asymptotic profiles of the positive steady state as one or both diffusion coefficients tend to infinity is established. This gives the most favored sites for the host and virus particles. Our results shed light on the interplay between spatial dispersal and disease dynamics and have implications for the design of effective control strategies.
{"title":"Behavior of a nonlocal species-pathogen system with varied dispersal mechanisms in heterogeneous habitats","authors":"Boumdiene Guenad , Salih Djilali , Soufiane Bentout","doi":"10.1016/j.cam.2026.117341","DOIUrl":"10.1016/j.cam.2026.117341","url":null,"abstract":"<div><div>This research is about a nonlocal dispersal host-pathogen model with Neumann boundary conditions. The nonlocal dispersion operator lacks compactness, which generates an additional challenge in showing the existence of a global compact attractor, and then the stability of the steady states. Therefore, we study the asymptotic stability of the positive steady states, where we show that depends on <em>R</em><sub>0</sub>. For <em>R</em><sub>0</sub> < 1, we prove the global asymptotic stability of the pathogen-free steady state, whereas for <em>R</em><sub>0</sub> > 1, we demonstrate the model’s uniform persistence and the existence of a positive steady state. Moreover, we establish the global behavior of the positive steady state for two cases: (i) the spatially homogeneous case, with both dispersal coefficients are not a zero, (ii) the spatially heterogeneous case, with one of the dispersion rate is a zero. Finally, the asymptotic profiles of the positive steady state as one or both diffusion coefficients tend to infinity is established. This gives the most favored sites for the host and virus particles. Our results shed light on the interplay between spatial dispersal and disease dynamics and have implications for the design of effective control strategies.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117341"},"PeriodicalIF":2.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979453","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}
Pub Date : 2026-01-07DOI: 10.1016/j.cam.2026.117351
Mohamed Kamel RIAHI
In this paper, we introduce novel fast matrix inversion algorithms that leverage triangular decomposition and a recurrent formalism, incorporating Strassen’s fast matrix multiplication algorithm. Our focus lies on triangular matrices, where we propose a unique computational approach based on combinatorial techniques for directly inverting general non-singular triangular matrices. Unlike iterative methods, our combinatorial approach enables the direct construction of the inverse through nonlinear combinations of carefully selected matrix entries, allowing full parallelization and efficient implementation on parallel architectures. Although combinatorial algorithms often suffer from exponential time complexity, limiting their practical use, our method overcomes this by deriving recurrent relations that facilitate recursive triangular splitting, striking a balance between efficiency and accuracy. We provide rigorous mathematical proofs to validate the approach and present extensive numerical experiments demonstrating its effectiveness.
Additionally, we develop several innovative numerical linear algebra algorithms that directly factorize the inverse of general matrices, with significant potential for generating preconditioners that accelerate Krylov subspace iterative solvers and improve the solution of large-scale linear systems.
Our comprehensive evaluation confirms that the proposed algorithms outperform classical approaches in terms of computational efficiency, opening up new avenues for advanced matrix inversion techniques and the development of effective preconditioning strategies.
{"title":"Combinatorial and recurrent approaches for efficient matrix inversion: Sub-cubic algorithms leveraging fast matrix products","authors":"Mohamed Kamel RIAHI","doi":"10.1016/j.cam.2026.117351","DOIUrl":"10.1016/j.cam.2026.117351","url":null,"abstract":"<div><div>In this paper, we introduce novel fast matrix inversion algorithms that leverage triangular decomposition and a recurrent formalism, incorporating Strassen’s fast matrix multiplication algorithm. Our focus lies on triangular matrices, where we propose a unique computational approach based on combinatorial techniques for directly inverting general non-singular triangular matrices. Unlike iterative methods, our combinatorial approach enables the direct construction of the inverse through nonlinear combinations of carefully selected matrix entries, allowing full parallelization and efficient implementation on parallel architectures. Although combinatorial algorithms often suffer from exponential time complexity, limiting their practical use, our method overcomes this by deriving recurrent relations that facilitate recursive triangular splitting, striking a balance between efficiency and accuracy. We provide rigorous mathematical proofs to validate the approach and present extensive numerical experiments demonstrating its effectiveness.</div><div>Additionally, we develop several innovative numerical linear algebra algorithms that directly factorize the inverse of general matrices, with significant potential for generating preconditioners that accelerate Krylov subspace iterative solvers and improve the solution of large-scale linear systems.</div><div>Our comprehensive evaluation confirms that the proposed algorithms outperform classical approaches in terms of computational efficiency, opening up new avenues for advanced matrix inversion techniques and the development of effective preconditioning strategies.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117351"},"PeriodicalIF":2.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979373","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}
Pub Date : 2026-01-07DOI: 10.1016/j.cam.2025.117332
Guohe Deng, Yurong Xie
Pricing options on the maximum or the minimum of several underlying assets (called extremum options) has always been one of the key problems in financial engineering because of high dimensionality. In this paper, we consider the pricing problem of European-style vulnerable extremum options under the Heston model and stochastic interest rate model in which the mean-reversion levels of both variance and interest rate processes are modulated by a continuous-time Markov chain with finite states. Integral representations for the pricing formulas of the vulnerable extremum options are derived by using the Esscher transform, joint characteristic function and multivariate Fourier transform technique. Then we provide the efficient approximation to calculate the semi-analytical pricing formulas of this option using the modified discrete fast Fourier transform (FFT) approach and examine the accuracy of the approximation by Monte Carlo simulation. Finally, numerical results for the prices or (and) its Delta values of the vulnerable extremum call options arising in the proposed model are given in a two-regime case. Further, the effect of introducing regime-switching into both the Heston model and stochastic interest rate model is investigated, and the sensitivity analysis of different parameters in this model on the option price are provided. Numerical experiments are provided to illustrate the significance of regime-switching risk in option pricing.
{"title":"Pricing vulnerable extremum options in a Markov regime-switching Heston’s model and stochastic interest rate","authors":"Guohe Deng, Yurong Xie","doi":"10.1016/j.cam.2025.117332","DOIUrl":"10.1016/j.cam.2025.117332","url":null,"abstract":"<div><div>Pricing options on the maximum or the minimum of several underlying assets (called extremum options) has always been one of the key problems in financial engineering because of high dimensionality. In this paper, we consider the pricing problem of European-style vulnerable extremum options under the Heston model and stochastic interest rate model in which the mean-reversion levels of both variance and interest rate processes are modulated by a continuous-time Markov chain with finite states. Integral representations for the pricing formulas of the vulnerable extremum options are derived by using the Esscher transform, joint characteristic function and multivariate Fourier transform technique. Then we provide the efficient approximation to calculate the semi-analytical pricing formulas of this option using the modified discrete fast Fourier transform (FFT) approach and examine the accuracy of the approximation by Monte Carlo simulation. Finally, numerical results for the prices or (and) its Delta values of the vulnerable extremum call options arising in the proposed model are given in a two-regime case. Further, the effect of introducing regime-switching into both the Heston model and stochastic interest rate model is investigated, and the sensitivity analysis of different parameters in this model on the option price are provided. Numerical experiments are provided to illustrate the significance of regime-switching risk in option pricing.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"482 ","pages":"Article 117332"},"PeriodicalIF":2.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928204","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}
Pub Date : 2026-01-06DOI: 10.1016/j.cam.2026.117350
Xue-Lei Lin , Chengyu Chen , Ye Liu , Huifang Yuan
The alternating direction implicit (ADI) scheme is a type of well-known fast solvable scheme, which is frequently studied for time-dependent problems with constant coefficients on rectangular domains. Due to the complicated algebraic matrix structure, it is rare to study the ADI schemes for time-dependent problems with variable coefficients on irregular domains in the literature. In this paper, we study a novel ADI scheme for the well-known challenging problem: convection-dominated convection diffusion equation with variable coefficients on two-dimensional irregular domain. An upwind difference scheme is proposed for the spatial discretization, which leads to diagonally dominant spatial discretization matrices. The ADI temporal discretization reduces the two-dimension spatial problem into two one-dimension spatial sub-problems, in which the sub-problem along x-direction has a tridiagonal structure while the sub-problem along y-direction is sparse and unstructured due to the complicated domain geometry. To handle the complicated structure of the y-sub-problems, a grid adaptive permutation technique is proposed to convert the y-sub-problems into tridiagonal systems. As a result, all the one-dimension sub-problems arising from the proposed ADI schemes are diagonally dominant tridiagonal systems, which can be fast and directly solved by banded LU factorization with optimal complexity (i.e., linear complexity). It is well-known that the complicated domain geometry and the dominance of the convection terms bring challenge to numerical solution of the equation. Remarkably, both theoretical results and numerical results show that the proposed scheme is unconditionally stable with respect to the dominance of the convection term, time-space grid ratio and is flexible to the domain geometry.
{"title":"An ADI scheme for convection diffusion equation with variable coefficients on irregular domain","authors":"Xue-Lei Lin , Chengyu Chen , Ye Liu , Huifang Yuan","doi":"10.1016/j.cam.2026.117350","DOIUrl":"10.1016/j.cam.2026.117350","url":null,"abstract":"<div><div>The alternating direction implicit (ADI) scheme is a type of well-known fast solvable scheme, which is frequently studied for time-dependent problems with constant coefficients on rectangular domains. Due to the complicated algebraic matrix structure, it is rare to study the ADI schemes for time-dependent problems with variable coefficients on irregular domains in the literature. In this paper, we study a novel ADI scheme for the well-known challenging problem: convection-dominated convection diffusion equation with variable coefficients on two-dimensional irregular domain. An upwind difference scheme is proposed for the spatial discretization, which leads to diagonally dominant spatial discretization matrices. The ADI temporal discretization reduces the two-dimension spatial problem into two one-dimension spatial sub-problems, in which the sub-problem along <em>x</em>-direction has a tridiagonal structure while the sub-problem along <em>y</em>-direction is sparse and unstructured due to the complicated domain geometry. To handle the complicated structure of the <em>y</em>-sub-problems, a grid adaptive permutation technique is proposed to convert the <em>y</em>-sub-problems into tridiagonal systems. As a result, all the one-dimension sub-problems arising from the proposed ADI schemes are diagonally dominant tridiagonal systems, which can be fast and directly solved by banded LU factorization with optimal complexity (i.e., linear complexity). It is well-known that the complicated domain geometry and the dominance of the convection terms bring challenge to numerical solution of the equation. Remarkably, both theoretical results and numerical results show that the proposed scheme is unconditionally stable with respect to the dominance of the convection term, time-space grid ratio and is flexible to the domain geometry.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"483 ","pages":"Article 117350"},"PeriodicalIF":2.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982029","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}