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
Moment Problems in Hereditary Function Spaces 遗传函数空间中的矩问题
IF 0.6
Concrete Operators Pub Date : 2019-01-01 DOI: 10.1515/conop-2019-0006
F. Vasilescu
{"title":"Moment Problems in Hereditary Function Spaces","authors":"F. Vasilescu","doi":"10.1515/conop-2019-0006","DOIUrl":"https://doi.org/10.1515/conop-2019-0006","url":null,"abstract":"Abstract We introduce a concept of hereditary set of multi-indices, and consider vector spaces of functions generated by families associated to such sets of multi-indices, called hereditary function spaces. Existence and uniquenes of representing measures for some abstract truncated moment problems are investigated in this framework, by adapting the concept of idempotent and that of dimensional stability, and using some techniques involving C*-algebras and commuting self-adjoint multiplication operators.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49030342","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: 2
On unbounded commuting Jacobi operators and some related issues 关于无界可换Jacobi算子及其相关问题
IF 0.6
Concrete Operators Pub Date : 2019-01-01 DOI: 10.1515/conop-2019-0008
A. Osipov
{"title":"On unbounded commuting Jacobi operators and some related issues","authors":"A. Osipov","doi":"10.1515/conop-2019-0008","DOIUrl":"https://doi.org/10.1515/conop-2019-0008","url":null,"abstract":"Abstract We consider the situations, when two unbounded operators generated by infinite Jacobi matrices, are self-adjoint and commute. It is found that if two Jacobi matrices formally commute, then two corresponding operators are either self-adjoint and commute, or admit a commuting self-adjoint extensions. In the latter case such extensions are explicitly described. Also, some necessary and sufficient conditions for self-adjointness of Jacobi operators are studied.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44236007","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
Berezin number inequalities for operators 算子的Berezin数不等式
IF 0.6
Concrete Operators Pub Date : 2019-01-01 DOI: 10.1515/conop-2019-0003
M. Bakherad, M. Garayev
{"title":"Berezin number inequalities for operators","authors":"M. Bakherad, M. Garayev","doi":"10.1515/conop-2019-0003","DOIUrl":"https://doi.org/10.1515/conop-2019-0003","url":null,"abstract":"Abstract The Berezin transform à of an operator A, acting on the reproducing kernel Hilbert space ℋ = ℋ (Ω) over some (non-empty) set Ω, is defined by Ã(λ) = 〉Aǩ λ, ǩ λ〈 (λ ∈ Ω), where k⌢λ=kλ‖ kλ ‖ ${mathord{buildrel{lower3pthbox{$scriptscriptstylefrown$}}over k} _lambda } = {{{k_lambda }} over {left| {{k_lambda }} right|}}$ is the normalized reproducing kernel of ℋ. The Berezin number of an operator A is defined by ber(A)=supλ∈Ω| A˜(λ) |=supλ∈Ω| 〈 Ak⌢λ,k⌢λ 〉 | ${bf{ber}}{rm{(}}A) = mathop {sup }limits_{lambda in Omega } left| {tilde A(lambda )} right| = mathop {sup }limits_{lambda in Omega } left| {leftlangle {A{{mathord{buildrel{lower3pthbox{$scriptscriptstylefrown$}}over k} }_lambda },{{mathord{buildrel{lower3pthbox{$scriptscriptstylefrown$}}over k} }_lambda }} rightrangle } right|$ . In this paper, we prove some Berezin number inequalities. Among other inequalities, it is shown that if A, B, X are bounded linear operators on a Hilbert space ℋ, then ber(AX±XA)⩽ber12(A*A+AA*)ber12(X*X+XX*) $${bf{ber}}(AX pm XA) leqslant {bf{be}}{{bf{r}}^{{1 over 2}}}left( {A*A + AA*} right){bf{be}}{{bf{r}}^{{1 over 2}}}left( {X*X + XX*} right)$$ and ber2(A*XB)⩽‖ X ‖2ber(A*A)ber(B*B). $${bf{be}}{{bf{r}}^2}({A^*}XB) leqslant {left| X right|^2}{bf{ber}}({A^*}A){bf{ber}}({B^*}B).$$ We also prove the multiplicative inequality ber(AB)⩽ber(A)ber(B) $${bf{ber}}(AB){bf{ber}}(A){bf{ber}}(B)$$","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42422999","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: 38
The Blum-Hanson Property Blum-Hanson物业
IF 0.6
Concrete Operators Pub Date : 2019-01-01 DOI: 10.1515/conop-2019-0009
S. Grivaux
{"title":"The Blum-Hanson Property","authors":"S. Grivaux","doi":"10.1515/conop-2019-0009","DOIUrl":"https://doi.org/10.1515/conop-2019-0009","url":null,"abstract":"Abstract Given a (real or complex, separable) Banach space, and a contraction T on X, we say that T has the Blum-Hanson property if whenever x, y ∈ X are such that Tnx tends weakly to y in X as n tends to infinity, the means 1N∑k=1NTnkx {1 over N}sumlimits_{k = 1}^N {{T^{{n_k}}}x} tend to y in norm for every strictly increasing sequence (nk) k≥1 of integers. The space X itself has the Blum-Hanson property if every contraction on X has the Blum-Hanson property. We explain the ergodic-theoretic motivation for the Blum-Hanson property, prove that Hilbert spaces have the Blum-Hanson property, and then present a recent criterion of a geometric flavor, due to Lefèvre-Matheron-Primot, which allows to retrieve essentially all the known examples of spaces with the Blum-Hanson property. Lastly, following Lefèvre-Matheron, we characterize the compact metric spaces K such that the space C(K) has the Blum-Hanson property.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45295023","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
Somewhere Dense Orbit that is not Dense on a Complex Hilbert Space 复Hilbert空间上某个不稠密的稠密轨道
IF 0.6
Concrete Operators Pub Date : 2019-01-01 DOI: 10.1515/conop-2019-0005
Neema Wilberth, Marco Mpimbo, Santosh Kumar
{"title":"Somewhere Dense Orbit that is not Dense on a Complex Hilbert Space","authors":"Neema Wilberth, Marco Mpimbo, Santosh Kumar","doi":"10.1515/conop-2019-0005","DOIUrl":"https://doi.org/10.1515/conop-2019-0005","url":null,"abstract":"Abstract In this paper, we present the existence of n-tuple of operators on complex Hilbert space that has a somewhere dense orbit and is not dense. We give the solution to the question stated in [11]: “Is there n-tuple of operators on a complex Hilbert space that has a somewhere dense orbit that is not dense?” We do so by extending the results due to Feldman [11] and Leòn-Saavedra [12] to complex Hilbert space. Further illustrative examples of somewhere dense orbits are given to support the results.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49344022","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
A note on bi-contractive projections on spaces of vector valued continuous functions 向量值连续函数空间上的双压缩投影
IF 0.6
Concrete Operators Pub Date : 2018-12-01 DOI: 10.1515/conop-2018-0005
F. Botelho, T. Rao
{"title":"A note on bi-contractive projections on spaces of vector valued continuous functions","authors":"F. Botelho, T. Rao","doi":"10.1515/conop-2018-0005","DOIUrl":"https://doi.org/10.1515/conop-2018-0005","url":null,"abstract":"Abstract This paper concerns the analysis of the structure of bi-contractive projections on spaces of vector valued continuous functions and presents results that extend the characterization of bi-contractive projections given by the first author. It also includes a partial generalization of these results to affine and vector valued continuous functions from a Choquet simplex into a Hilbert space.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2018-0005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44499822","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
Weyl asymptotics for perturbations of Morse potential and connections to the Riemann zeta function Morse势扰动的Weyl渐近性及其与Riemann-zeta函数的联系
IF 0.6
Concrete Operators Pub Date : 2018-11-12 DOI: 10.1515/conop-2022-0139
R. Rahm
{"title":"Weyl asymptotics for perturbations of Morse potential and connections to the Riemann zeta function","authors":"R. Rahm","doi":"10.1515/conop-2022-0139","DOIUrl":"https://doi.org/10.1515/conop-2022-0139","url":null,"abstract":"Abstract Let N ( T ; V ) Nleft(T;hspace{0.33em}V) denote the number of eigenvalues of the Schrödinger operator − y ″ + V y -{y}^{^{primeprime} }+Vy with absolute value less than T T . This article studies the Weyl asymptotics of perturbations of the Schrödinger operator − y ″ + 1 4 e 2 t y -{y}^{^{primeprime} }+frac{1}{4}{e}^{2t}y on [ x 0 , ∞ ) left[{x}_{0},infty ) . In particular, we show that perturbations by functions ε ( t ) varepsilon left(t) that satisfy ∣ ε ( t ) ∣ ≲ e t | varepsilon left(t)| hspace{0.33em}lesssim hspace{0.33em}{e}^{t} do not change the Weyl asymptotics very much. Special emphasis is placed on connections to the asymptotics of the zeros of the Riemann zeta function.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46486561","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
Some remarks on the Dirichlet problem on infinite trees 关于无限树上Dirichlet问题的几点注记
IF 0.6
Concrete Operators Pub Date : 2018-11-06 DOI: 10.1515/conop-2019-0002
Nikolaos Chalmoukis, Matteo Levi
{"title":"Some remarks on the Dirichlet problem on infinite trees","authors":"Nikolaos Chalmoukis, Matteo Levi","doi":"10.1515/conop-2019-0002","DOIUrl":"https://doi.org/10.1515/conop-2019-0002","url":null,"abstract":"Abstract We consider the Dirichlet problem on in_nite and locally _nite rooted trees, andwe prove that the set of irregular points for continuous data has zero capacity. We also give some uniqueness results for solutions in Sobolev W1,p of the tree.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2018-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46497583","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
The Distribution Function for a Polynomial 多项式的分布函数
IF 0.6
Concrete Operators Pub Date : 2018-11-01 DOI: 10.1515/conop-2018-0004
J. Cima, W. Derrick
{"title":"The Distribution Function for a Polynomial","authors":"J. Cima, W. Derrick","doi":"10.1515/conop-2018-0004","DOIUrl":"https://doi.org/10.1515/conop-2018-0004","url":null,"abstract":"Abstract This paper explores the continuity and differentiability properties for the distribution function for a polynomial","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2018-0004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49428908","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
Quaternionic inner and outer functions 四元数内部和外部函数
IF 0.6
Concrete Operators Pub Date : 2018-10-23 DOI: 10.1515/conop-2019-0004
A. Monguzzi, G. Sarfatti, D. Seco
{"title":"Quaternionic inner and outer functions","authors":"A. Monguzzi, G. Sarfatti, D. Seco","doi":"10.1515/conop-2019-0004","DOIUrl":"https://doi.org/10.1515/conop-2019-0004","url":null,"abstract":"Abstract We study properties of inner and outer functions in the Hardy space of the quaternionic unit ball. In particular, we give sufficient conditions as well as necessary ones for functions to be inner or outer.","PeriodicalId":53800,"journal":{"name":"Concrete Operators","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2018-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/conop-2019-0004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45056067","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
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