Complex Analysis and Operator Theory最新文献_第3页

Spectral Analysis of an Operator with Fourier-Neumann Expansions Beneath 带有傅里叶-诺伊曼展开的算子的谱分析

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-17 DOI: 10.1007/s11785-024-01577-3

Krzysztof Stempak

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Toeplitz and Hankel Operators on Vector-Valued Fock-Type Spaces 向量值福克型空间上的托普利兹和汉克尔算子

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-17 DOI: 10.1007/s11785-024-01575-5

Chunxu Xu, Jianxiang Dong, Tao Yu

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Clark Measures on Bounded Symmetric Domains 有界对称域上的克拉克量纲

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-11 DOI: 10.1007/s11785-024-01571-9

Mattia Calzi

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A Generalization of Ando’s Dilation, and Isometric Dilations for a Class of Tuples of q-Commuting Contractions 安藤扩张的一般化，以及一类 q 对等收缩元组的等距扩张

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-10 DOI: 10.1007/s11785-024-01551-z

Sibaprasad Barik, Bappa Bisai

{"title":"A Generalization of Ando’s Dilation, and Isometric Dilations for a Class of Tuples of q-Commuting Contractions","authors":"Sibaprasad Barik, Bappa Bisai","doi":"10.1007/s11785-024-01551-z","DOIUrl":"https://doi.org/10.1007/s11785-024-01551-z","url":null,"abstract":"Given a bounded operator Q on a Hilbert space (mathcal {H}), a pair of bounded operators ((T_1,T_2)) on (mathcal {H}) is said to be Q-commuting if one of the following holds: $$begin{aligned} T_1T_2=QT_2T_1 text { or }T_1T_2=T_2QT_1 text { or }T_1T_2=T_2T_1Q. end{aligned}$$We give an explicit construction of isometric dilations for pairs of Q-commuting contractions for unitary Q, which generalizes the isometric dilation of Ando (Acta Sci Math (Szeged) 24:88–90, 1963) for pairs of commuting contractions. In particular, for (Q=qI_{mathcal {H}}), where q is a complex number of modulus 1, this gives, as a corollary, an explicit construction of isometric dilations for pairs of q-commuting contractions, which are well studied. There is an extended notion of q-commutativity for general tuples of operators and it is known that isometric dilation does not hold, in general, for an n-tuple of q-commuting contractions, where (nge 3). Generalizing the class of commuting contractions considered by Brehmer (Acta Sci Math (Szeged) 22:106–111, 1961), we construct a class of n-tuples of q-commuting contractions and find isometric dilations explicitly for the class.","PeriodicalId":50654,"journal":{"name":"Complex Analysis and Operator Theory","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141577676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deformations and q-Convolutions. Old and New Results 变形与 q-自旋。新旧成果

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-07 DOI: 10.1007/s11785-024-01572-8

Marek Bożejko, Wojciech Bożejko

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Generalized Volterra Integral Operators on Fock Spaces Fock 空间上的广义 Volterra 积分算子

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-05 DOI: 10.1007/s11785-024-01573-7

Yongqing Liu

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On the Expansion of Resolvents and the Integrated Density of States for Poisson Distributed Schrödinger Operators 论泊松分布式薛定谔算子的残留物展开和综合状态密度

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-04 DOI: 10.1007/s11785-024-01546-w

David Hasler, Jannis Koberstein

引用次数: 0

On the Differentiation of Integrals in Measure Spaces Along Filters: II 论沿着滤波器的测度空间积分微分：二

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-03 DOI: 10.1007/s11785-024-01552-y

Fausto Di Biase, Steven G. Krantz

{"title":"On the Differentiation of Integrals in Measure Spaces Along Filters: II","authors":"Fausto Di Biase, Steven G. Krantz","doi":"10.1007/s11785-024-01552-y","DOIUrl":"https://doi.org/10.1007/s11785-024-01552-y","url":null,"abstract":"Let X be a complete measure space of finite measure. The Lebesgue transform of an integrable function f on X encodes the collection of all the mean-values of f on all measurable subsets of X of positive measure. In the problem of the differentiation of integrals, one seeks to recapture f from its Lebesgue transform. In previous work we showed that, in all known results, f may be recaptured from its Lebesgue transform by means of a limiting process associated to an appropriate family of filters defined on the collection ({{,mathrm{{mathcal {A}}},}}) of all measurable subsets of X of positive measure. The first result of the present work is that the existence of such a limiting process is equivalent to the existence of a Von Neumann-Maharam lifting of X. In the second result of this work we provide an independent argument that shows that the recourse to filters is a necessary consequence of the requirement that the process of recapturing f from its mean-values is associated to a natural transformation, in the sense of category theory. This result essentially follows from the Yoneda lemma. As far as we know, this is the first instance of a significant interaction between category theory and the problem of the differentiation of integrals. In the Appendix we have proved, in a precise sense, that natural transformations fall within the general concept of homomorphism. As far as we know, this is a novel conclusion: Although it is often said that natural transformations are homomorphisms of functors, this statement appears to be presented as a mere analogy, not in a precise technical sense. In order to achieve this result, we had to bring to the foreground a notion that is implicit in the subject but has remained hidden in the background, i.e., that of partial magma.","PeriodicalId":50654,"journal":{"name":"Complex Analysis and Operator Theory","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Toeplitz Operators Associated with the Hypergeometric Gabor Transform and Applications 与超几何 Gabor 变换相关的托普利兹算子及其应用

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-01 DOI: 10.1007/s11785-024-01569-3

Hatem Mejjaoli

引用次数: 0

S-Nodes, Factorisation of Spectral Matrix Functions and Corresponding Inequalities S 节点、谱矩阵函数因式分解及相应不等式

IF 0.8 4区数学

Complex Analysis and Operator Theory Pub Date : 2024-07-01 DOI: 10.1007/s11785-024-01567-5

Alexander Sakhnovich

引用次数: 0