Yige Liao , Li-Bin Liu , Xianbing Luo , Guangqing Long
{"title":"求解空间位移非定常奇摄动问题的Crank-Nicolson超弱不连续Galerkin方法","authors":"Yige Liao , Li-Bin Liu , Xianbing Luo , Guangqing Long","doi":"10.1016/j.aml.2025.109736","DOIUrl":null,"url":null,"abstract":"<div><div>In this paper, a unsteady singularly perturbed problem (SPP) with a shift in space is studied. The problem is discretized by a ultra-weak discontinuous Galerkin (UWDG) method in space on the Bakhvalov-type (B-type) mesh and by Crank–Nicolson (CN) scheme in time. Through carefully designing numerical fluxes and penalty terms, we rigorously establish the coercivity of the bilinear form associated with the UWDG scheme. Furthermore, based on the <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-projection and careful error estimate for Ritz projection, we derive optimal-order convergence estimates. Numerical experiments verify the effectiveness of the method.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":"172 ","pages":"Article 109736"},"PeriodicalIF":2.8000,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A Crank–Nicolson ultra-weak discontinuous Galerkin method for solving a unsteady singularly perturbed problem with a shift in space\",\"authors\":\"Yige Liao , Li-Bin Liu , Xianbing Luo , Guangqing Long\",\"doi\":\"10.1016/j.aml.2025.109736\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>In this paper, a unsteady singularly perturbed problem (SPP) with a shift in space is studied. The problem is discretized by a ultra-weak discontinuous Galerkin (UWDG) method in space on the Bakhvalov-type (B-type) mesh and by Crank–Nicolson (CN) scheme in time. Through carefully designing numerical fluxes and penalty terms, we rigorously establish the coercivity of the bilinear form associated with the UWDG scheme. Furthermore, based on the <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-projection and careful error estimate for Ritz projection, we derive optimal-order convergence estimates. Numerical experiments verify the effectiveness of the method.</div></div>\",\"PeriodicalId\":55497,\"journal\":{\"name\":\"Applied Mathematics Letters\",\"volume\":\"172 \",\"pages\":\"Article 109736\"},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2025-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Mathematics Letters\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0893965925002861\",\"RegionNum\":2,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Mathematics Letters","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0893965925002861","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
A Crank–Nicolson ultra-weak discontinuous Galerkin method for solving a unsteady singularly perturbed problem with a shift in space
In this paper, a unsteady singularly perturbed problem (SPP) with a shift in space is studied. The problem is discretized by a ultra-weak discontinuous Galerkin (UWDG) method in space on the Bakhvalov-type (B-type) mesh and by Crank–Nicolson (CN) scheme in time. Through carefully designing numerical fluxes and penalty terms, we rigorously establish the coercivity of the bilinear form associated with the UWDG scheme. Furthermore, based on the -projection and careful error estimate for Ritz projection, we derive optimal-order convergence estimates. Numerical experiments verify the effectiveness of the method.
期刊介绍:
The purpose of Applied Mathematics Letters is to provide a means of rapid publication for important but brief applied mathematical papers. The brief descriptions of any work involving a novel application or utilization of mathematics, or a development in the methodology of applied mathematics is a potential contribution for this journal. This journal''s focus is on applied mathematics topics based on differential equations and linear algebra. Priority will be given to submissions that are likely to appeal to a wide audience.