Pub Date : 2023-10-18DOI: 10.1365/s13291-023-00273-z
Barbara Verfürth
Abstract Multiscale high-contrast media can cause astonishing wave propagation phenomena through resonance effects. For instance, waves could be exponentially damped independent of the incident angle or waves could be re-focused as through a lense. In this review article, we discuss the numerical treatment of wave propagation through multiscale high-contrast media at the example of the Helmholtz equation. First, we briefly summarize the findings of analytical homogenization theory, which inspire the design of numerical methods and indicate interesting regimes for simulation. In the main part, we discuss two different classes of numerical multiscale methods and focus on how to treat especially high-contrast media. Some elements of a priori error analysis are discussed as well. Various numerical simulations showcase the applicability of the numerical methods to explore unusual wave phenomena, for instance exponential damping and lensing with flat interfaces.
{"title":"Numerical Multiscale Methods for Waves in High-Contrast Media","authors":"Barbara Verfürth","doi":"10.1365/s13291-023-00273-z","DOIUrl":"https://doi.org/10.1365/s13291-023-00273-z","url":null,"abstract":"Abstract Multiscale high-contrast media can cause astonishing wave propagation phenomena through resonance effects. For instance, waves could be exponentially damped independent of the incident angle or waves could be re-focused as through a lense. In this review article, we discuss the numerical treatment of wave propagation through multiscale high-contrast media at the example of the Helmholtz equation. First, we briefly summarize the findings of analytical homogenization theory, which inspire the design of numerical methods and indicate interesting regimes for simulation. In the main part, we discuss two different classes of numerical multiscale methods and focus on how to treat especially high-contrast media. Some elements of a priori error analysis are discussed as well. Various numerical simulations showcase the applicability of the numerical methods to explore unusual wave phenomena, for instance exponential damping and lensing with flat interfaces.","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-11DOI: 10.1365/s13291-023-00272-0
Friedrich Wagemann
{"title":"Cohomology of Leibniz Algebras","authors":"Friedrich Wagemann","doi":"10.1365/s13291-023-00272-0","DOIUrl":"https://doi.org/10.1365/s13291-023-00272-0","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136063826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1365/s13291-023-00270-2
B. Sanderse
{"title":"G. Rozza, G. Stabile, F. Ballarin: “Advanced Reduced Order Methods and Applications in Computational Fluid Dynamics”","authors":"B. Sanderse","doi":"10.1365/s13291-023-00270-2","DOIUrl":"https://doi.org/10.1365/s13291-023-00270-2","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"105 1","pages":"191 - 194"},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79549137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-22DOI: 10.1365/s13291-023-00268-w
Li Guo, S. Paycha, Bin Zhang
{"title":"Mathematical Reflections on Locality","authors":"Li Guo, S. Paycha, Bin Zhang","doi":"10.1365/s13291-023-00268-w","DOIUrl":"https://doi.org/10.1365/s13291-023-00268-w","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"153 1","pages":"1-42"},"PeriodicalIF":0.0,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73146978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-07DOI: 10.1365/s13291-023-00266-y
Caroline Lassueur
{"title":"A Tour of \u0000 \u0000 \u0000 \u0000 \u0000 p\u0000 \u0000 $p$\u0000 -Permutation Modules and Related Classes of Modules","authors":"Caroline Lassueur","doi":"10.1365/s13291-023-00266-y","DOIUrl":"https://doi.org/10.1365/s13291-023-00266-y","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"20 1","pages":"1-53"},"PeriodicalIF":0.0,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79227834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01Epub Date: 2022-11-09DOI: 10.1365/s13291-022-00263-7
Roland Steinbauer
On the occasion of Sir Roger Penrose's 2020 Nobel Prize in Physics, we review the singularity theorems of General Relativity, as well as their recent extension to Lorentzian metrics of low regularity. The latter is motivated by the quest to explore the nature of the singularities predicted by the classical theorems. Aiming at the more mathematically minded reader, we give a pedagogical introduction to the classical theorems with an emphasis on the analytical side of the arguments. We especially concentrate on focusing results for causal geodesics under appropriate geometric and initial conditions, in the smooth and in the low regularity case. The latter comprise the main technical advance that leads to the proofs of -singularity theorems via a regularisation approach that allows to deal with the distributional curvature. We close with an overview on related lines of research and a future outlook.
{"title":"The Singularity Theorems of General Relativity and Their Low Regularity Extensions.","authors":"Roland Steinbauer","doi":"10.1365/s13291-022-00263-7","DOIUrl":"10.1365/s13291-022-00263-7","url":null,"abstract":"<p><p>On the occasion of Sir Roger Penrose's 2020 Nobel Prize in Physics, we review the singularity theorems of General Relativity, as well as their recent extension to Lorentzian metrics of low regularity. The latter is motivated by the quest to explore the nature of the singularities predicted by the classical theorems. Aiming at the more mathematically minded reader, we give a pedagogical introduction to the classical theorems with an emphasis on the analytical side of the arguments. We especially concentrate on focusing results for causal geodesics under appropriate geometric and initial conditions, in the smooth and in the low regularity case. The latter comprise the main technical advance that leads to the proofs of <math><msup><mi>C</mi><mn>1</mn></msup></math>-singularity theorems via a regularisation approach that allows to deal with the distributional curvature. We close with an overview on related lines of research and a future outlook.</p>","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"125 2","pages":"73-119"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10228498/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9566938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-24DOI: 10.1365/s13291-022-00262-8
Nicola M. R. Oswald, Jörn Steuding, K. Volkert
{"title":"Zum Einhundertsten Geburtstag des Lokal-Global–Prinzips in der Zahlentheorie","authors":"Nicola M. R. Oswald, Jörn Steuding, K. Volkert","doi":"10.1365/s13291-022-00262-8","DOIUrl":"https://doi.org/10.1365/s13291-022-00262-8","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"65 1","pages":"239 - 257"},"PeriodicalIF":0.0,"publicationDate":"2022-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78708244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-20DOI: 10.1365/s13291-022-00261-9
J. B. Olsson
{"title":"Christine Bessenrodt (1958-2022)","authors":"J. B. Olsson","doi":"10.1365/s13291-022-00261-9","DOIUrl":"https://doi.org/10.1365/s13291-022-00261-9","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"31 1","pages":"207 - 213"},"PeriodicalIF":0.0,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90805756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-13DOI: 10.1365/s13291-022-00259-3
Stefan Witzel
{"title":"Dmitry N. Kozlov: “Organized Collapse: An Introduction to Discrete Morse Theory”","authors":"Stefan Witzel","doi":"10.1365/s13291-022-00259-3","DOIUrl":"https://doi.org/10.1365/s13291-022-00259-3","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"32 1","pages":"273 - 279"},"PeriodicalIF":0.0,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90974807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-13DOI: 10.1365/s13291-022-00258-4
Lidia Angeleri Hügel
{"title":"Henning Krause: “Homological Theory of Representations”","authors":"Lidia Angeleri Hügel","doi":"10.1365/s13291-022-00258-4","DOIUrl":"https://doi.org/10.1365/s13291-022-00258-4","url":null,"abstract":"","PeriodicalId":73532,"journal":{"name":"Jahresbericht der Deutschen Mathematiker-Vereinigung. Deutsche Mathematiker-Vereinigung","volume":"29 1","pages":"267 - 272"},"PeriodicalIF":0.0,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88815205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}