{"title":"On the numerical radius of weighted shift operators with generalized geometric weights","authors":"Bikshan Chakraborty, Sarita Ojha","doi":"10.1016/j.jmaa.2024.129021","DOIUrl":null,"url":null,"abstract":"<div><div>In this paper, we give bounds on the numerical radius of the weighted shift operator <em>T</em> with generalized geometric weights<span><span><span><math><mrow><mo>(</mo><mn>1</mn><mo>,</mo><mi>s</mi><mi>q</mi><mo>,</mo><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>,</mo><mi>s</mi><msup><mrow><mi>q</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>,</mo><mo>…</mo><mo>,</mo><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn><mi>n</mi><mo>−</mo><mn>2</mn></mrow></msup><mo>,</mo><mi>s</mi><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup><mo>,</mo><mo>…</mo><mo>)</mo></mrow><mo>,</mo></math></span></span></span> where <span><math><mi>s</mi><mo>></mo><mn>0</mn></math></span> and <span><math><mn>0</mn><mo><</mo><mi>q</mi><mo><</mo><mn>1</mn></math></span>. Also, we provide the entire function <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>T</mi></mrow></msub><mo>(</mo><mi>z</mi><mo>)</mo></math></span> whose minimal positive root gives the numerical radius of the weighted shift operator <em>T</em>. The purpose of this paper is to generalize the results of numerical radius for the weighted shift operator with geometric weights given in <span><span>[5]</span></span>.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 2","pages":"Article 129021"},"PeriodicalIF":1.2000,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Mathematical Analysis and Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022247X24009430","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, we give bounds on the numerical radius of the weighted shift operator T with generalized geometric weights where and . Also, we provide the entire function whose minimal positive root gives the numerical radius of the weighted shift operator T. The purpose of this paper is to generalize the results of numerical radius for the weighted shift operator with geometric weights given in [5].
期刊介绍:
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