{"title":"阴影、双曲性和阿鲁特奇变换","authors":"C. A. Morales, T. T. Linh","doi":"10.1007/s10998-024-00597-y","DOIUrl":null,"url":null,"abstract":"<p>We introduce the concept of <span>\\(\\epsilon \\)</span>-homoclinic points for invertible linear operators on Banach spaces. We establish that an operator is hyperbolic if and only if it possesses the shadowing property without any nonzero <span>\\(\\epsilon \\)</span>-homoclinic points (for some <span>\\(\\epsilon >0\\)</span>). Additionally, we demonstrate that a linear operator on a Banach space <i>X</i> exhibiting the shadowing property is uniformly contracting, uniformly expanding, possesses a nontrivial invariant closed subspace, or has a dense set of bounded orbits in <i>X</i>. Moreover, we demonstrate the invariance of the set of generalized hyperbolic operators under <span>\\(\\lambda \\)</span>-Aluthge transforms, where <span>\\(\\lambda \\in \\left( 0, 1\\right) \\)</span>. Additionally, we establish that the Aluthge iterates of an invertible operator converge to a hyperbolic operator solely when the initial operator is hyperbolic. Finally, we prove that the Aluthge iterates of hyponormal shifted hyperbolic weighted shifts diverge and also the existence of hyperbolic weighted shifts with divergent Aluthge iterates.</p>","PeriodicalId":49706,"journal":{"name":"Periodica Mathematica Hungarica","volume":"1 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Shadowing, hyperbolicity, and Aluthge transforms\",\"authors\":\"C. A. Morales, T. T. Linh\",\"doi\":\"10.1007/s10998-024-00597-y\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We introduce the concept of <span>\\\\(\\\\epsilon \\\\)</span>-homoclinic points for invertible linear operators on Banach spaces. We establish that an operator is hyperbolic if and only if it possesses the shadowing property without any nonzero <span>\\\\(\\\\epsilon \\\\)</span>-homoclinic points (for some <span>\\\\(\\\\epsilon >0\\\\)</span>). Additionally, we demonstrate that a linear operator on a Banach space <i>X</i> exhibiting the shadowing property is uniformly contracting, uniformly expanding, possesses a nontrivial invariant closed subspace, or has a dense set of bounded orbits in <i>X</i>. Moreover, we demonstrate the invariance of the set of generalized hyperbolic operators under <span>\\\\(\\\\lambda \\\\)</span>-Aluthge transforms, where <span>\\\\(\\\\lambda \\\\in \\\\left( 0, 1\\\\right) \\\\)</span>. Additionally, we establish that the Aluthge iterates of an invertible operator converge to a hyperbolic operator solely when the initial operator is hyperbolic. Finally, we prove that the Aluthge iterates of hyponormal shifted hyperbolic weighted shifts diverge and also the existence of hyperbolic weighted shifts with divergent Aluthge iterates.</p>\",\"PeriodicalId\":49706,\"journal\":{\"name\":\"Periodica Mathematica Hungarica\",\"volume\":\"1 1\",\"pages\":\"\"},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2024-07-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Periodica Mathematica Hungarica\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1007/s10998-024-00597-y\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Periodica Mathematica Hungarica","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s10998-024-00597-y","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
We introduce the concept of \(\epsilon \)-homoclinic points for invertible linear operators on Banach spaces. We establish that an operator is hyperbolic if and only if it possesses the shadowing property without any nonzero \(\epsilon \)-homoclinic points (for some \(\epsilon >0\)). Additionally, we demonstrate that a linear operator on a Banach space X exhibiting the shadowing property is uniformly contracting, uniformly expanding, possesses a nontrivial invariant closed subspace, or has a dense set of bounded orbits in X. Moreover, we demonstrate the invariance of the set of generalized hyperbolic operators under \(\lambda \)-Aluthge transforms, where \(\lambda \in \left( 0, 1\right) \). Additionally, we establish that the Aluthge iterates of an invertible operator converge to a hyperbolic operator solely when the initial operator is hyperbolic. Finally, we prove that the Aluthge iterates of hyponormal shifted hyperbolic weighted shifts diverge and also the existence of hyperbolic weighted shifts with divergent Aluthge iterates.
期刊介绍:
Periodica Mathematica Hungarica is devoted to publishing research articles in all areas of pure and applied mathematics as well as theoretical computer science. To be published in the Periodica, a paper must be correct, new, and significant. Very strong submissions (upon the consent of the author) will be redirected to Acta Mathematica Hungarica.
Periodica Mathematica Hungarica is the journal of the Hungarian Mathematical Society (János Bolyai Mathematical Society). The main profile of the journal is in pure mathematics, being open to applied mathematical papers with significant mathematical content.