{"title":"Banach空间中度量投影的弱星可扩性、拟弱星近可扩性和连续性","authors":"Laiyou Bao, Suyalatu Wulede","doi":"10.7153/oam-2022-16-68","DOIUrl":null,"url":null,"abstract":". The relations between the w ∗ dentability and Chebyshev set or the continuity of metric projection operator are given. Let X ∗ be the conjugate space of Banach space X , the conditions of a point ( x ∗ , y ∗ ) on the unit sphere of product space X ∗ × X ∗ to be w ∗ denting point of closed unit ball of product space X ∗ × X ∗ are given. Also, a notion of quasi-w ∗ near dentability in conjugate space X ∗ is introduced and the relations between the quasi-w ∗ nearly denting point of closed unit ball of X ∗ and a certain slice of closed unit ball of X ∗ are given.","PeriodicalId":56274,"journal":{"name":"Operators and Matrices","volume":"1 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Weak-star dentability, quasi-weak-star near dentability and continuity of metric projector in Banach spaces\",\"authors\":\"Laiyou Bao, Suyalatu Wulede\",\"doi\":\"10.7153/oam-2022-16-68\",\"DOIUrl\":null,\"url\":null,\"abstract\":\". The relations between the w ∗ dentability and Chebyshev set or the continuity of metric projection operator are given. Let X ∗ be the conjugate space of Banach space X , the conditions of a point ( x ∗ , y ∗ ) on the unit sphere of product space X ∗ × X ∗ to be w ∗ denting point of closed unit ball of product space X ∗ × X ∗ are given. Also, a notion of quasi-w ∗ near dentability in conjugate space X ∗ is introduced and the relations between the quasi-w ∗ nearly denting point of closed unit ball of X ∗ and a certain slice of closed unit ball of X ∗ are given.\",\"PeriodicalId\":56274,\"journal\":{\"name\":\"Operators and Matrices\",\"volume\":\"1 1\",\"pages\":\"\"},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2022-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Operators and Matrices\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.7153/oam-2022-16-68\",\"RegionNum\":4,\"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":"Operators and Matrices","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.7153/oam-2022-16-68","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
Weak-star dentability, quasi-weak-star near dentability and continuity of metric projector in Banach spaces
. The relations between the w ∗ dentability and Chebyshev set or the continuity of metric projection operator are given. Let X ∗ be the conjugate space of Banach space X , the conditions of a point ( x ∗ , y ∗ ) on the unit sphere of product space X ∗ × X ∗ to be w ∗ denting point of closed unit ball of product space X ∗ × X ∗ are given. Also, a notion of quasi-w ∗ near dentability in conjugate space X ∗ is introduced and the relations between the quasi-w ∗ nearly denting point of closed unit ball of X ∗ and a certain slice of closed unit ball of X ∗ are given.
期刊介绍:
''Operators and Matrices'' (''OaM'') aims towards developing a high standard international journal which will publish top quality research and expository papers in matrix and operator theory and their applications. The journal will publish mainly pure mathematics, but occasionally papers of a more applied nature could be accepted. ''OaM'' will also publish relevant book reviews.
''OaM'' is published quarterly, in March, June, September and December.