一个被遗忘的Pełczyński定理:$(\lambda +)$-内射空间不一定是$\lambda $-内射- $\lambda \in(1,2)$的情况

IF 0.7 3区 数学 Q2 MATHEMATICS Studia Mathematica Pub Date : 2022-01-19 DOI:10.4064/sm220119-25-6
Tomasz Kania, G. Lewicki
{"title":"一个被遗忘的Pełczyński定理:$(\\lambda +)$-内射空间不一定是$\\lambda $-内射- $\\lambda \\in(1,2)$的情况","authors":"Tomasz Kania, G. Lewicki","doi":"10.4064/sm220119-25-6","DOIUrl":null,"url":null,"abstract":". Isbell and Semadeni [Trans. Amer. Math. Soc. 107 (1963)] proved that every infinite-dimensional 1-injective Banach space contains a hyperplane that is (2+ ε )-injective for every ε > 0, yet is is not 2-injective and remarked in a footnote that Pe lczy´nski had proved for every λ > 1 the existence of a ( λ + ε )-injective space ( ε > 0) that is not λ injective. Unfortunately, no trace of the proof of Pe lczy´nski’s result has been preserved. In the present paper, we establish the said theorem for λ ∈ (1 , 2] by constructing an appropriate renorming of ℓ ∞ . This contrasts (at least for real scalars) with the case λ = 1 for which Lindenstrauss [Mem. Amer. Math. Soc. 48 (1964)] proved the contrary statement.","PeriodicalId":51179,"journal":{"name":"Studia Mathematica","volume":" ","pages":""},"PeriodicalIF":0.7000,"publicationDate":"2022-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A forgotten theorem of Pełczyński: $(\\\\lambda +)$-injective spaces need not be $\\\\lambda $-injective—the case $\\\\lambda \\\\in (1,2]$\",\"authors\":\"Tomasz Kania, G. Lewicki\",\"doi\":\"10.4064/sm220119-25-6\",\"DOIUrl\":null,\"url\":null,\"abstract\":\". Isbell and Semadeni [Trans. Amer. Math. Soc. 107 (1963)] proved that every infinite-dimensional 1-injective Banach space contains a hyperplane that is (2+ ε )-injective for every ε > 0, yet is is not 2-injective and remarked in a footnote that Pe lczy´nski had proved for every λ > 1 the existence of a ( λ + ε )-injective space ( ε > 0) that is not λ injective. Unfortunately, no trace of the proof of Pe lczy´nski’s result has been preserved. In the present paper, we establish the said theorem for λ ∈ (1 , 2] by constructing an appropriate renorming of ℓ ∞ . This contrasts (at least for real scalars) with the case λ = 1 for which Lindenstrauss [Mem. Amer. Math. Soc. 48 (1964)] proved the contrary statement.\",\"PeriodicalId\":51179,\"journal\":{\"name\":\"Studia Mathematica\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":0.7000,\"publicationDate\":\"2022-01-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Studia Mathematica\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.4064/sm220119-25-6\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Studia Mathematica","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.4064/sm220119-25-6","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0

摘要

Isbell和Semadeni[Trans.Amer.Math.Soc.107(1963)]证明了每个有限维1-内射Banach空间都包含一个超平面,对于每个ε>0都是(2+ε)-内射的,但不是2-内射的。不幸的是,佩尔奇·恩斯基的结果没有任何证据被保留下来。在本文中,我们通过构造ℓ ∞ . 这与Lindenstrauss[Mem.Amer.Math.Soc.48(1964)]证明相反陈述的情况λ=1形成了对比(至少对于实标量)。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
A forgotten theorem of Pełczyński: $(\lambda +)$-injective spaces need not be $\lambda $-injective—the case $\lambda \in (1,2]$
. Isbell and Semadeni [Trans. Amer. Math. Soc. 107 (1963)] proved that every infinite-dimensional 1-injective Banach space contains a hyperplane that is (2+ ε )-injective for every ε > 0, yet is is not 2-injective and remarked in a footnote that Pe lczy´nski had proved for every λ > 1 the existence of a ( λ + ε )-injective space ( ε > 0) that is not λ injective. Unfortunately, no trace of the proof of Pe lczy´nski’s result has been preserved. In the present paper, we establish the said theorem for λ ∈ (1 , 2] by constructing an appropriate renorming of ℓ ∞ . This contrasts (at least for real scalars) with the case λ = 1 for which Lindenstrauss [Mem. Amer. Math. Soc. 48 (1964)] proved the contrary statement.
求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
Studia Mathematica
Studia Mathematica 数学-数学
CiteScore
1.50
自引率
12.50%
发文量
72
审稿时长
5 months
期刊介绍: The journal publishes original papers in English, French, German and Russian, mainly in functional analysis, abstract methods of mathematical analysis and probability theory.
期刊最新文献
A biparameter decomposition of Davis–Garsia type Embeddings between Lorentz sequence spaces are strictly but not finitely strictly singular Symmetric stable processes on amenable groups The $L^p$-to-$L^q$ compactness of commutators with $p \gt q$ $L^p$-boundedness of pseudo-differential operators on homogeneous trees
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1