发布求助
文献互助 智能选刊 最新文献

Concrete Operators最新文献

筛选
英文 中文
Applications of the Sylvester operator in the space of slice semi-regular functions Sylvester算子在切片半正则函数空间中的应用
IF 0.6
Concrete Operators Pub Date : 2020-01-01 DOI: 10.1515/conop-2020-0001
Altavilla Amedeo, C. de Fabritiis
{"title":"Applications of the Sylvester operator in the space of slice semi-regular functions","authors":"Altavilla Amedeo, C. de Fabritiis","doi":"10.1515/conop-2020-0001","DOIUrl":"https://doi.org/10.1515/conop-2020-0001","url":null,"abstract":"Abstract In this paper we apply the results obtained in [3] to establish some outcomes of the study of the behaviour of a class of linear operators, which include the Sylvester ones, acting on slice semi-regular functions. We first present a detailed study of the kernel of the linear operator ℒf,g (when not trivial), showing that it has dimension 2 if exactly one between f and g is a zero divisor, and it has dimension 3 if both f and g are zero divisors. Afterwards, we deepen the analysis of the behaviour of the -product, giving a complete classification of the cases when the functions fv, gv and fv gv are linearly dependent and obtaining, as a by-product, a necessary and sufficient condition on the functions f and g in order their *-product is slice-preserving. At last, we give an Embry-type result which classifies the functions f and g such that for any function h commuting with f + g and f * g, we have that h commutes with f and g, too.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"1 - 12"},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48746531","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}
引用次数: 4
From ℋ∞ to 𝒩. Pointwise properties and algebraic structure in the Nevanlinna class 从h∞到h∞。Nevanlinna类的点态性质和代数结构
IF 0.6
Concrete Operators Pub Date : 2020-01-01 DOI: 10.1515/conop-2020-0007
X. Massaneda, P. Thomas
{"title":"From ℋ∞ to 𝒩. Pointwise properties and algebraic structure in the Nevanlinna class","authors":"X. Massaneda, P. Thomas","doi":"10.1515/conop-2020-0007","DOIUrl":"https://doi.org/10.1515/conop-2020-0007","url":null,"abstract":"Abstract This survey shows how, for the Nevanlinna class 𝒩 of the unit disc, one can define and often characterize the analogues of well-known objects and properties related to the algebra of bounded analytic functions ℋ∞: interpolating sequences, Corona theorem, sets of determination, stable rank, as well as the more recent notions of Weak Embedding Property and threshold of invertibility for quotient algebras. The general rule we observe is that a given result for ℋ∞ can be transposed to 𝒩 by replacing uniform bounds by a suitable control by positive harmonic functions. We show several instances where this rule applies, as well as some exceptions. We also briefly discuss the situation for the related Smirnov class.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"91 - 115"},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66888745","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}
引用次数: 0
Bounds of operators on the Hilbert sequence space Hilbert序列空间上算子的界
IF 0.6
Concrete Operators Pub Date : 2020-01-01 DOI: 10.1515/conop-2020-0104
H. Roopaei
{"title":"Bounds of operators on the Hilbert sequence space","authors":"H. Roopaei","doi":"10.1515/conop-2020-0104","DOIUrl":"https://doi.org/10.1515/conop-2020-0104","url":null,"abstract":"Abstract The author has computed the bounds of the Hilbert operator on some sequence spaces [18, 19]. Through this study the author has investigated the bounds of operators on the Hilbert sequence space and the present study is a complement of those previous research.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"91 6","pages":"155 - 165"},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41259915","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}
引用次数: 7
Joint numerical ranges: recent advances and applications minicourse by V. Müller and Yu. Tomilov 联合数值范围：V.Müller和Yu的微型课程的最新进展和应用。托米洛夫
IF 0.6
Concrete Operators Pub Date : 2020-01-01 DOI: 10.1515/conop-2020-0102
V. Müller, Y. Tomilov
{"title":"Joint numerical ranges: recent advances and applications minicourse by V. Müller and Yu. Tomilov","authors":"V. Müller, Y. Tomilov","doi":"10.1515/conop-2020-0102","DOIUrl":"https://doi.org/10.1515/conop-2020-0102","url":null,"abstract":"Abstract We present a survey of some recent results concerning joint numerical ranges of n-tuples of Hilbert space operators, accompanied with several new observations and remarks. Thereafter, numerical ranges techniques will be applied to various problems of operator theory. In particular, we discuss problems concerning orbits of operators, diagonals of operators and their tuples, and pinching problems. Lastly, motivated by known results on the numerical radius of a single operator, we examine whether, given bounded linear operators T1, . . ., Tn on a Hilbert space H, there exists a unit vector x ∈ H such that |〈Tjx, x〉| is “large” for all j = 1, . . . , n.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"133 - 154"},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48040870","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}
引用次数: 6
Approximation and entropy numbers of composition operators 复合算子的近似和熵数
IF 0.6
Concrete Operators Pub Date : 2020-01-01 DOI: 10.1515/conop-2020-0106
Daniel Li, H. Queffélec, L. Rodríguez-Piazza
{"title":"Approximation and entropy numbers of composition operators","authors":"Daniel Li, H. Queffélec, L. Rodríguez-Piazza","doi":"10.1515/conop-2020-0106","DOIUrl":"https://doi.org/10.1515/conop-2020-0106","url":null,"abstract":"Abstract We give a survey on approximation numbers of composition operators on the Hardy space, on the disk and on the polydisk, and add corresponding new results on their entropy numbers, revealing how they are different.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"166 - 179"},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43624388","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}
引用次数: 1
Weighted Sub-Bergman Hilbert spaces in the unit ball of ℂn 单位球中加权Sub-Bergman Hilbert空间
IF 0.6
Concrete Operators Pub Date : 2020-01-01 DOI: 10.1515/conop-2020-0103
R. Rososzczuk, F. Symesak
{"title":"Weighted Sub-Bergman Hilbert spaces in the unit ball of ℂn","authors":"R. Rososzczuk, F. Symesak","doi":"10.1515/conop-2020-0103","DOIUrl":"https://doi.org/10.1515/conop-2020-0103","url":null,"abstract":"Abstract In this note, we study defect operators in the case of holomorphic functions of the unit ball of ℂn. These operators are built from weighted Bergman kernel with a holomorphic vector. We obtain a description of sub-Hilbert spaces and we give a sufficient condition so that theses spaces are the same.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"124 - 132"},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42424333","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}
引用次数: 3
Riesz means on homogeneous trees Riesz的意思是齐次树
IF 0.6
Concrete Operators Pub Date : 2019-09-13 DOI: 10.1515/conop-2020-0111
E. Papageorgiou
{"title":"Riesz means on homogeneous trees","authors":"E. Papageorgiou","doi":"10.1515/conop-2020-0111","DOIUrl":"https://doi.org/10.1515/conop-2020-0111","url":null,"abstract":"Abstract Let 𝕋 be a homogeneous tree. We prove that if f ∈ Lp(𝕋), 1 ≤ p ≤ 2, then the Riesz means SzR (f) converge to f everywhere as R → ∞, whenever Re z > 0.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"8 1","pages":"60 - 65"},"PeriodicalIF":0.6,"publicationDate":"2019-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42972388","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}
引用次数: 0
Hausdorff operators on Bergman spaces of the upper half plane 上半平面Bergman空间上的Hausdorff算子
IF 0.6
Concrete Operators Pub Date : 2019-07-19 DOI: 10.1515/conop-2020-0005
G. Stylogiannis
{"title":"Hausdorff operators on Bergman spaces of the upper half plane","authors":"G. Stylogiannis","doi":"10.1515/conop-2020-0005","DOIUrl":"https://doi.org/10.1515/conop-2020-0005","url":null,"abstract":"Abstract In this paper we study Hausdorff operators on the Bergman spaces Ap(𝕌) of the upper half plane.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"69 - 80"},"PeriodicalIF":0.6,"publicationDate":"2019-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43855177","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}
引用次数: 12
On Determinant Expansions for Hankel Operators 关于Hankel算子的行列式展开
IF 0.6
Concrete Operators Pub Date : 2019-01-17 DOI: 10.1515/conop-2020-0002
G. Blower, Yang Chen
{"title":"On Determinant Expansions for Hankel Operators","authors":"G. Blower, Yang Chen","doi":"10.1515/conop-2020-0002","DOIUrl":"https://doi.org/10.1515/conop-2020-0002","url":null,"abstract":"Abstract Let w be a semiclassical weight that is generic in Magnus’s sense, and (pn)n=0∞ ({p_n})_{n = 0}^infty the corresponding sequence of orthogonal polynomials. We express the Christoffel–Darboux kernel as a sum of products of Hankel integral operators. For ψ ∈ L∞ (iℝ), let W(ψ) be the Wiener-Hopf operator with symbol ψ. We give sufficient conditions on ψ such that 1/ det W(ψ) W(ψ−1) = det(I − Γϕ1 Γϕ2) where Γϕ1 and Γϕ2 are Hankel operators that are Hilbert–Schmidt. For certain, ψ Barnes’s integral leads to an expansion of this determinant in terms of the generalised hypergeometric 2mF2m-1. These results extend those of Basor and Chen [2], who obtained 4F3 likewise. We include examples where the Wiener–Hopf factors are found explicitly.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"7 1","pages":"13 - 44"},"PeriodicalIF":0.6,"publicationDate":"2019-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2020-0002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45543622","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}
引用次数: 1
On the closed range problem for composition operators on the Dirichlet space 狄利克雷空间上复合算子的闭合范围问题
IF 0.6
Concrete Operators Pub Date : 2019-01-01 DOI: 10.1515/conop-2019-0007
N. Zorboska
{"title":"On the closed range problem for composition operators on the Dirichlet space","authors":"N. Zorboska","doi":"10.1515/conop-2019-0007","DOIUrl":"https://doi.org/10.1515/conop-2019-0007","url":null,"abstract":"Abstract We characterize closed range composition operators on the Dirichlet space for a particular class of composition symbols. The characterization relies on a result about Fredholm Toeplitz operators with BMO1 symbols, and with Berezin transforms of vanishing oscillation.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":"6 1","pages":"76 - 81"},"PeriodicalIF":0.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41448201","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}
引用次数: 1
首页 上一页 下一页 尾页
0
×
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
请完成安全验证×
相关产品
×
本文献相关产品
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 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信