Pub Date : 2024-09-16DOI: 10.1007/s10476-024-00049-2
I. Blahota, D. Nagy
We consider the norm convergence for a special matrix-based de la Vallée Poussin-like mean of Fourier series with respect to the Vilenkin system. We estimate the difference between the named mean above and the corresponding function in norm, and the upper estimation is given by the modulus of continuity of the function. We also give theorems with respect to norm and almost everywhere convergences.
我们考虑了基于特殊矩阵的 de la Vallée Poussin 类傅里叶级数均值对 Vilenkin 系统的规范收敛性。我们估算了上面命名的均值与相应函数在规范上的差异,上估算值由函数的连续性模量给出。我们还给出了关于常模和几乎无处不收敛的定理。
{"title":"Approximation by a special de la Vallée Poussin type matrix transform mean of Vilenkin–Fourier series","authors":"I. Blahota, D. Nagy","doi":"10.1007/s10476-024-00049-2","DOIUrl":"10.1007/s10476-024-00049-2","url":null,"abstract":"<div><p>We consider the norm convergence for a special matrix-based de la Vallée Poussin-like mean of Fourier series with respect to the Vilenkin system. \u0000We estimate the difference between the named mean above and the corresponding function in norm, and the upper estimation is given by the modulus of \u0000continuity of the function. We also give theorems with respect to norm and almost everywhere convergences.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"50 3","pages":"939 - 957"},"PeriodicalIF":0.6,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1007/s10476-024-00051-8
Y. C. Gao, K. Liu, F. N. Wang
In this paper, we continue to consider the value cross-sharing problems on meromorphic functions. We mainly present some results and improvements on (f(z)) and (g(z)) provided that (f(z)) and (g^{(k)}(z)) share common values together with (g(z)) and (f^{(k)}(z)) share the same or different common values CM or IM, where (f(z), g(z)) are meromorphic functions and (k) is a positive integer. With additional conditions on deficiency, we get more accurate relations on (f(z)) and (g(z)) when (f(z)) and (g^{(k)}(z)) share a CM together with (g(z)) and (f^{(k)}(z)) share b CM, where a, b are constants.
在本文中,我们将继续考虑关于同态函数的值交叉共享问题。我们主要介绍了在(f(z))和(g(z))共享公共值以及(g(z))和(f^{(k)}(z))共享相同或不同的公共值 CM 或 IM 的前提下,关于(f(z))和(g(z))的一些结果和改进、其中,(f(z), g(z))都是同态函数,(k)是正整数。当 (f(z)) 和 (g^{(k)}(z)) 共享一个 CM,同时 (g(z)) 和 (f^{(k)}(z)) 共享 b 个 CM,其中 a、b 为常数时,通过附加的缺陷条件,我们可以得到关于 (f(z)) 和 (g(z)) 的更精确的关系。
{"title":"Value cross-sharing problems on meromorphic functions","authors":"Y. C. Gao, K. Liu, F. N. Wang","doi":"10.1007/s10476-024-00051-8","DOIUrl":"https://doi.org/10.1007/s10476-024-00051-8","url":null,"abstract":"<p>In this paper, we continue to consider the value cross-sharing problems on meromorphic functions. We mainly present some results and improvements on <span>(f(z))</span> and <span>(g(z))</span> provided that <span>(f(z))</span> and <span>(g^{(k)}(z))</span> share common values together with <span>(g(z))</span> and <span>(f^{(k)}(z))</span> share the same or different common values CM or IM, where <span>(f(z), g(z))</span> are meromorphic functions and <span>(k)</span> is a positive integer. With additional conditions on deficiency, we get more accurate relations on <span>(f(z))</span> and <span>(g(z))</span> when <span>(f(z))</span> and <span>(g^{(k)}(z))</span> share a CM together with <span>(g(z))</span> and <span>(f^{(k)}(z))</span> share <i>b</i> CM, where <i>a</i>, <i>b</i> are constants.</p>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"20 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00045-6
V. Kovač, B. Predojević
We study a distance graph (Gamma_n) that is isomorphic to the (1)-skeleton of an (n)-dimensional unit hypercube. We show that every measurable set of positive upper Banach density in the plane contains all sufficiently large dilates of (Gamma_n). This provides the first examples of distance graphs other than the trees for which a dimensionally sharp embedding in positive density sets is known.
{"title":"Large dilates of hypercube graphs in the plane","authors":"V. Kovač, B. Predojević","doi":"10.1007/s10476-024-00045-6","DOIUrl":"10.1007/s10476-024-00045-6","url":null,"abstract":"<div><p>We study a distance graph <span>(Gamma_n)</span> that is isomorphic to the <span>(1)</span>-skeleton of an <span>(n)</span>-dimensional unit hypercube. We show that every measurable set of positive upper Banach density in the plane contains all sufficiently large dilates of <span>(Gamma_n)</span>. This provides the first examples of distance graphs other than the trees for which a dimensionally sharp embedding in positive density sets is known.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"50 3","pages":"893 - 915"},"PeriodicalIF":0.6,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00044-7
N. Evseev, A. Menovschikov
The notion of decomposable operators acting between distinct (L^p)-direct integrals of Banach spaces is introduced. We show that these operators generalize the composition operator in the sense that a binary relation replaces a mapping. The necessary and sufficient conditions for the boundedness of those operators are the main results of the paper.
{"title":"Decomposable operators acting between distinct (L^p)-direct integrals of Banach spaces","authors":"N. Evseev, A. Menovschikov","doi":"10.1007/s10476-024-00044-7","DOIUrl":"10.1007/s10476-024-00044-7","url":null,"abstract":"<div><p>The notion of decomposable operators acting between distinct <span>(L^p)</span>-direct \u0000integrals of Banach spaces is introduced. We show that these operators generalize the composition operator in the sense that a binary relation replaces a \u0000mapping. The necessary and sufficient conditions for the boundedness of those operators are the main results of the paper.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"50 3","pages":"861 - 892"},"PeriodicalIF":0.6,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00043-8
Y. Chen
Motivated by [19] and [10], we define the modified proximity function (overline{m}_{q}(f,r)) for entire curves in complex projective space (mathbf{P}^nmathbf{C}), and establish an asymptotic equality of Cartan's Second Main Theorem. This is a generalization of [19, Theorem 1.6] for transcendental meromorphic functions. Moreover, we strengthen the result to entire curves of finite order and holomorphic mappings over multiple variables.
{"title":"An asymptotic equality of Cartan's Second Main Theorem and some generalizations","authors":"Y. Chen","doi":"10.1007/s10476-024-00043-8","DOIUrl":"https://doi.org/10.1007/s10476-024-00043-8","url":null,"abstract":"<p>Motivated by [19] and [10], we define the modified proximity function <span>(overline{m}_{q}(f,r))</span> for entire curves in complex projective space <span>(mathbf{P}^nmathbf{C})</span>, and establish an asymptotic equality of Cartan's Second Main Theorem. This is a generalization of [19, Theorem 1.6] for transcendental meromorphic functions. Moreover, we strengthen the result to entire curves of finite order and holomorphic mappings over multiple variables.\u0000</p>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"74 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00048-3
R. R. Akopyan, P. Kumar, G. V. Milovanović
For the polar derivative (D_alpha P(z) =nP(z)+(alpha-z)P'(z)) of a polynomial (P(z)) of degree n, most of the (L^p) inequalities available in the literature are for restricted values of (alpha), and in this paper we extend few such fundamental results to all of (alpha) in the complex plane.
{"title":"On the inequalities of Zygmund and de Bruijn","authors":"R. R. Akopyan, P. Kumar, G. V. Milovanović","doi":"10.1007/s10476-024-00048-3","DOIUrl":"10.1007/s10476-024-00048-3","url":null,"abstract":"<div><p>For the polar derivative <span>(D_alpha P(z) =nP(z)+(alpha-z)P'(z))</span> of \u0000a polynomial <span>(P(z))</span> of degree <i>n</i>, most of \u0000the <span>(L^p)</span> inequalities available in the literature are for restricted values of <span>(alpha)</span>, and in this \u0000paper we extend few such fundamental results to all of <span>(alpha)</span> in the complex plane.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"50 4","pages":"967 - 986"},"PeriodicalIF":0.6,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00047-4
L. Abadias, J. E. Galé, P. J. Miana, J. Oliva-Maza
We show that the composition hyperbolic group in the unit disc, once transferred to act on sequence spaces, is bounded on (ell^p) if and only if ({p=2}). We introduce some integral operators subordinated to that group which are natural generalizations of classical operators on sequences. For the description of such operators, we use some combinatorial identities which look interesting in their own.
{"title":"On the hyperbolic group and subordinated integrals as operators on sequence Banach spaces","authors":"L. Abadias, J. E. Galé, P. J. Miana, J. Oliva-Maza","doi":"10.1007/s10476-024-00047-4","DOIUrl":"https://doi.org/10.1007/s10476-024-00047-4","url":null,"abstract":"<p>We show that the composition hyperbolic group in the unit disc, once transferred to act on sequence spaces, is bounded on <span>(ell^p)</span> if and only if <span>({p=2})</span>. We introduce some integral operators subordinated to that group which are natural generalizations of classical operators on sequences. For the description of such operators, we use some combinatorial identities which look interesting in their own.</p>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"35 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00046-5
K. Matsumoto
In this paper, we study the strong extension groups of Cuntz–Krieger algebras, and present a formula to compute the groups. We also detect the position of the Toeplitz extension of a Cuntz–Krieger algebra in the strong extension group and in the weak extension group to see that the weak extension group with the position of the Toeplitz extension is a complete invariant of the isomorphism class of the Cuntz–Krieger algebra associated with its transposed matrix.
{"title":"On strong extension groups of Cuntz–Krieger algebras","authors":"K. Matsumoto","doi":"10.1007/s10476-024-00046-5","DOIUrl":"10.1007/s10476-024-00046-5","url":null,"abstract":"<div><p>In this paper, we study the strong extension groups of Cuntz–Krieger algebras, and present a formula to compute the groups. We also detect the position of the Toeplitz extension of a Cuntz–Krieger algebra in the strong extension group and in the weak extension group to see that the weak extension group with the position of the Toeplitz extension is a complete invariant of the isomorphism class of the Cuntz–Krieger algebra associated with its transposed matrix.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"50 3","pages":"917 - 937"},"PeriodicalIF":0.6,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s10476-024-00050-9
A. Chirvasitu
Each symmetrically-normed ideal (mathcal{I}) of compact operators on a Hilbert space (H) induces a multiplier topology (mu^*_{mathcal{I}}) on the algebra (mathcal{B}(H)) of bounded operators. We show that under fairly reasonable circumstances those topologies precisely reflect, strength-wise, the inclusion relations between the corresponding ideals, including the fact that the topologies are distinct when the ideals are.
Said circumstances apply, for instance, for the two-parameter chain of Lorentz ideals (mathcal{L}^{p,q}) interpolating between the ideals of trace-class and compact operators. This gives a totally ordered chain of distinct topologies (mu^*_{p,qmid 0}) on (mathcal{B}(H)), with (mu^*_{2,2mid 0}) being the (sigma mbox{-}strong^*) topology and (mu^*_{infty,inftymid 0}) the strict/Mackey topology. In particular, the latter are only two of a natural continuous family.
{"title":"Rich lattices of multiplier topologies","authors":"A. Chirvasitu","doi":"10.1007/s10476-024-00050-9","DOIUrl":"https://doi.org/10.1007/s10476-024-00050-9","url":null,"abstract":"<p>Each symmetrically-normed ideal <span>(mathcal{I})</span> of compact operators on a Hilbert space <span>(H)</span> induces a multiplier topology <span>(mu^*_{mathcal{I}})</span> on the algebra <span>(mathcal{B}(H))</span> of bounded operators. We show that under fairly reasonable circumstances those topologies precisely reflect, strength-wise, the inclusion relations between the corresponding ideals, including the fact that the topologies are distinct when the ideals are.</p><p>Said circumstances apply, for instance, for the two-parameter chain of Lorentz ideals <span>(mathcal{L}^{p,q})</span> interpolating between the ideals of trace-class and compact operators. This gives a totally ordered chain of distinct topologies <span>(mu^*_{p,qmid 0})</span> on <span>(mathcal{B}(H))</span>, with <span>(mu^*_{2,2mid 0})</span> being the <span>(sigma mbox{-}strong^*)</span> topology and <span>(mu^*_{infty,inftymid 0})</span> the strict/Mackey topology. In particular, the latter are only two of a natural continuous family. </p>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"32 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1007/s10476-024-00039-4
M. Gerlach
We generalize a fundamental theorem on positive matrix semigroups stating that each component is either strictly positive for all times or identically zero (“Lévy’s Theorem”). Our proof of this fact that does not require the matrices to be continuous at time zero. We also provide a formulation of this theorem in the terminology of positive operator semigroups on sequence spaces.
{"title":"A generalization of Lévy’s theorem on positive matrix semigroups","authors":"M. Gerlach","doi":"10.1007/s10476-024-00039-4","DOIUrl":"10.1007/s10476-024-00039-4","url":null,"abstract":"<div><p>We generalize a fundamental theorem on positive matrix semigroups stating that each component is either strictly positive for all times or identically zero (“Lévy’s Theorem”). Our proof of this fact that does not require the matrices to be continuous at time zero. We also provide a formulation of this theorem in the terminology of positive operator semigroups on sequence spaces.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"50 4","pages":"1019 - 1032"},"PeriodicalIF":0.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}