Pub Date : 2024-10-22DOI: 10.1016/j.jfa.2024.110708
Carlo Bellavita , Marco M. Peloso
In this paper we deal with the problem of describing the dual space of the Bernstein space , that is the space of entire functions of exponential type (at most) whose restriction to the real line is Lebesgue integrable. We provide several characterizations, showing that such dual space can be described as a quotient of the space of entire functions of exponential type κ whose restriction to the real line are in a suitable BMO-type space, or as the space of symbols b for which the Hankel operator is bounded on the Paley–Wiener space . We also provide a characterization of as the BMO space w.r.t. the Clark measures of the inner function on the upper half-plane, in analogy with the known description of the dual of backward-shift invariant 1-spaces on the torus. Furthermore, we show that the orthogonal projection induces a bounded operator from onto .
Finally, we show that is the dual space of a suitable VMO-type space or as the space of symbols b for which the Hankel operator on the Paley–Wiener space is compact.
{"title":"Duality, BMO and Hankel operators on Bernstein spaces","authors":"Carlo Bellavita , Marco M. Peloso","doi":"10.1016/j.jfa.2024.110708","DOIUrl":"10.1016/j.jfa.2024.110708","url":null,"abstract":"<div><div>In this paper we deal with the problem of describing the dual space <span><math><msup><mrow><mo>(</mo><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi></mrow><mrow><mn>1</mn></mrow></msubsup><mo>)</mo></mrow><mrow><mo>⁎</mo></mrow></msup></math></span> of the Bernstein space <span><math><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi></mrow><mrow><mn>1</mn></mrow></msubsup></math></span>, that is the space of entire functions of exponential type (at most) <span><math><mi>κ</mi><mo>></mo><mn>0</mn></math></span> whose restriction to the real line is Lebesgue integrable. We provide several characterizations, showing that such dual space can be described as a quotient of the space of entire functions of exponential type <em>κ</em> whose restriction to the real line are in a suitable BMO-type space, or as the space of symbols <em>b</em> for which the Hankel operator <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>b</mi></mrow></msub></math></span> is bounded on the Paley–Wiener space <span><math><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi><mo>/</mo><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>. We also provide a characterization of <span><math><msup><mrow><mo>(</mo><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi></mrow><mrow><mn>1</mn></mrow></msubsup><mo>)</mo></mrow><mrow><mo>⁎</mo></mrow></msup></math></span> as the BMO space w.r.t. the Clark measures of the inner function <span><math><msup><mrow><mi>e</mi></mrow><mrow><mi>i</mi><mn>2</mn><mi>κ</mi><mi>z</mi></mrow></msup></math></span> on the upper half-plane, in analogy with the known description of the dual of backward-shift invariant 1-spaces on the torus. Furthermore, we show that the orthogonal projection <span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>κ</mi></mrow></msub><mo>:</mo><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>(</mo><mi>R</mi><mo>)</mo><mo>→</mo><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> induces a bounded operator from <span><math><msup><mrow><mi>L</mi></mrow><mrow><mo>∞</mo></mrow></msup><mo>(</mo><mi>R</mi><mo>)</mo></math></span> onto <span><math><msup><mrow><mo>(</mo><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi></mrow><mrow><mn>1</mn></mrow></msubsup><mo>)</mo></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>.</div><div>Finally, we show that <span><math><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi></mrow><mrow><mn>1</mn></mrow></msubsup></math></span> is the dual space of a suitable VMO-type space or as the space of symbols <em>b</em> for which the Hankel operator <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>b</mi></mrow></msub></math></span> on the Paley–Wiener space <span><math><msubsup><mrow><mi>B</mi></mrow><mrow><mi>κ</mi><mo>/</mo><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> is compact.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110708"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1016/j.jfa.2024.110707
Tomasz Gałązka, Adam Osękowski
Let be a unit circle. Assume further that f is an element of the Hardy space and g belongs to the analytic BMO space on . The paper contains the identification of the optimal universal constant C in the estimate Actually, the inequality is studied in the stronger form, involving the Littlewood-Paley function on the left and the sharp maximal function of g on the right. The proof rests on the construction of an appropriate plurisuperharmonic function on a parabolic domain and the application of probabilistic techniques.
假设 T 是单位圆。本文包含对估计|12π∫Tf(ζ)‾g(ζ)dζ|≤C‖f‖H1(T)‖g‖BMO(T)中最优通用常数 C 的鉴定。实际上,不等式是以更强的形式研究的,左边涉及 Littlewood-Paley 函数,右边涉及 g 的尖锐最大函数。证明依赖于在抛物线域上构造一个适当的诸超谐函数以及概率技术的应用。
{"title":"Sharp analytic version of Fefferman's inequality","authors":"Tomasz Gałązka, Adam Osękowski","doi":"10.1016/j.jfa.2024.110707","DOIUrl":"10.1016/j.jfa.2024.110707","url":null,"abstract":"<div><div>Let <span><math><mi>T</mi></math></span> be a unit circle. Assume further that <em>f</em> is an element of the Hardy space <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>T</mi><mo>)</mo></math></span> and <em>g</em> belongs to the analytic <em>BMO</em> space on <span><math><mi>T</mi></math></span>. The paper contains the identification of the optimal universal constant <em>C</em> in the estimate<span><span><span><math><mrow><mo>|</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn><mi>π</mi></mrow></mfrac><munder><mo>∫</mo><mrow><mi>T</mi></mrow></munder><mover><mrow><mi>f</mi><mo>(</mo><mi>ζ</mi><mo>)</mo></mrow><mo>‾</mo></mover><mi>g</mi><mo>(</mo><mi>ζ</mi><mo>)</mo><mtext>d</mtext><mi>ζ</mi><mo>|</mo></mrow><mo>≤</mo><mi>C</mi><mspace></mspace><msub><mrow><mo>‖</mo><mi>f</mi><mo>‖</mo></mrow><mrow><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>T</mi><mo>)</mo></mrow></msub><msub><mrow><mo>‖</mo><mi>g</mi><mo>‖</mo></mrow><mrow><mi>B</mi><mi>M</mi><mi>O</mi><mo>(</mo><mi>T</mi><mo>)</mo></mrow></msub><mo>.</mo></math></span></span></span> Actually, the inequality is studied in the stronger form, involving the Littlewood-Paley function on the left and the sharp maximal function of <em>g</em> on the right. The proof rests on the construction of an appropriate plurisuperharmonic function on a parabolic domain and the application of probabilistic techniques.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110707"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1016/j.jfa.2024.110706
Lenny Neyt , Joachim Toft , Jasson Vindas
We establish Hermite expansion characterizations for several subspaces of the Fréchet space of functions on the real line satisfying In particular, we extend and improve Fourier characterizations of the so-called proper Pilipović spaces obtained in [21]. The main ingredients in our proofs are the Bargmann transform and some achieved optimal forms of the Phragmén-Lindelöf principle.
{"title":"Hermite expansions for spaces of functions with nearly optimal time-frequency decay","authors":"Lenny Neyt , Joachim Toft , Jasson Vindas","doi":"10.1016/j.jfa.2024.110706","DOIUrl":"10.1016/j.jfa.2024.110706","url":null,"abstract":"<div><div>We establish Hermite expansion characterizations for several subspaces of the Fréchet space of functions on the real line satisfying<span><span><span><math><mo>|</mo><mi>f</mi><mo>(</mo><mi>x</mi><mo>)</mo><mo>|</mo><mo>≲</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo><mo>(</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>−</mo><mi>λ</mi><mo>)</mo><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msup><mo>,</mo><mspace></mspace><mo>|</mo><mover><mrow><mi>f</mi></mrow><mrow><mo>ˆ</mo></mrow></mover><mo>(</mo><mi>ξ</mi><mo>)</mo><mo>|</mo><mo>≲</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo><mo>(</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>−</mo><mi>λ</mi><mo>)</mo><msup><mrow><mi>ξ</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></msup><mo>,</mo><mspace></mspace><mo>∀</mo><mi>λ</mi><mo>></mo><mn>0</mn><mo>.</mo></math></span></span></span> In particular, we extend and improve Fourier characterizations of the so-called proper Pilipović spaces obtained in <span><span>[21]</span></span>. The main ingredients in our proofs are the Bargmann transform and some achieved optimal forms of the Phragmén-Lindelöf principle.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 3","pages":"Article 110706"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-21DOI: 10.1016/j.jfa.2024.110704
Jitao Xu, Lifeng Zhao
In this paper, we study the energy critical 1-equivariant Landau-Lifschitz flow mapping to with arbitrary given coefficients . We prove that there exists a codimension one smooth well-localized set of initial data arbitrarily close to the ground state which generates type-II finite-time blowup solutions, and give a precise description of the corresponding singularity formation. In our proof, both the Schrödinger part and the heat part play important roles in the construction of approximate solutions and the mixed energy/Morawetz functional. However, the blowup rate is independent of the coefficients.
本文研究了任意给定系数ρ1∈R,ρ2>0的能量临界一等变Landau-Lifschitz流映射R2到S2。我们证明了存在一个任意接近基态的一维光滑良好局部初始数据集,该数据集会产生 II 型有限时间炸毁解,并给出了相应奇点形成的精确描述。在我们的证明中,薛定谔部分和热量部分在近似解和混合能量/莫拉维兹函数的构造中都发挥了重要作用。然而,炸毁率与系数无关。
{"title":"Blowup dynamics for smooth equivariant solutions to energy critical Landau-Lifschitz flow","authors":"Jitao Xu, Lifeng Zhao","doi":"10.1016/j.jfa.2024.110704","DOIUrl":"10.1016/j.jfa.2024.110704","url":null,"abstract":"<div><div>In this paper, we study the energy critical 1-equivariant Landau-Lifschitz flow mapping <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> to <span><math><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> with arbitrary given coefficients <span><math><msub><mrow><mi>ρ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>∈</mo><mi>R</mi><mo>,</mo><mspace></mspace><msub><mrow><mi>ρ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>></mo><mn>0</mn></math></span>. We prove that there exists a codimension one smooth well-localized set of initial data arbitrarily close to the ground state which generates type-II finite-time blowup solutions, and give a precise description of the corresponding singularity formation. In our proof, both the Schrödinger part and the heat part play important roles in the construction of approximate solutions and the mixed energy/Morawetz functional. However, the blowup rate is independent of the coefficients.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110704"},"PeriodicalIF":1.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.jfa.2024.110703
Jeet Sampat, Orr Moshe Shalit
We study algebras of bounded noncommutative (nc) functions on unit balls of operator spaces (nc operator balls) and on their subvarieties. Considering the example of the nc unit polydisk we show that these algebras, while having a natural operator algebra structure, might not be the multiplier algebra of any reasonable nc reproducing kernel Hilbert space (RKHS). After examining additional subtleties of the nc RKHS approach, we turn to study the structure and representation theory of these algebras using function theoretic and operator algebraic tools. We show that the underlying nc variety is a complete invariant for the algebra of uniformly continuous nc functions on a homogeneous subvariety, in the sense that two such algebras are completely isometrically isomorphic if and only if the subvarieties are nc biholomorphic. We obtain extension and rigidity results for nc maps between subvarieties of nc operator balls corresponding to injective spaces that imply that a biholomorphism between homogeneous varieties extends to a biholomorphism between the ambient balls, which can be modified to a linear isomorphism. Thus, the algebra of uniformly continuous nc functions on nc operator balls, and even its restriction to certain subvarieties, completely determine the operator space up to completely isometric isomorphism.
{"title":"On the classification of function algebras on subvarieties of noncommutative operator balls","authors":"Jeet Sampat, Orr Moshe Shalit","doi":"10.1016/j.jfa.2024.110703","DOIUrl":"10.1016/j.jfa.2024.110703","url":null,"abstract":"<div><div>We study algebras of bounded noncommutative (nc) functions on unit balls of operator spaces (nc operator balls) and on their subvarieties. Considering the example of the nc unit polydisk we show that these algebras, while having a natural operator algebra structure, might not be the multiplier algebra of any reasonable nc reproducing kernel Hilbert space (RKHS). After examining additional subtleties of the nc RKHS approach, we turn to study the structure and representation theory of these algebras using function theoretic and operator algebraic tools. We show that the underlying nc variety is a complete invariant for the algebra of uniformly continuous nc functions on a homogeneous subvariety, in the sense that two such algebras are completely isometrically isomorphic if and only if the subvarieties are nc biholomorphic. We obtain extension and rigidity results for nc maps between subvarieties of nc operator balls corresponding to injective spaces that imply that a biholomorphism between homogeneous varieties extends to a biholomorphism between the ambient balls, which can be modified to a linear isomorphism. Thus, the algebra of uniformly continuous nc functions on nc operator balls, and even its restriction to certain subvarieties, completely determine the operator space up to completely isometric isomorphism.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110703"},"PeriodicalIF":1.7,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.jfa.2024.110701
Yong Jiao, Hui Li, Sijie Luo, Lian Wu
<div><div>Let <span><math><mo>(</mo><mi>M</mi><mo>,</mo><mi>τ</mi><mo>)</mo></math></span> be a noncommutative probability space equipped with a filtration <span><math><msub><mrow><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>)</mo></mrow><mrow><mi>t</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></msub></math></span> whose union is <span><math><msup><mrow><mi>w</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>-dense in <span><math><mi>M</mi></math></span>, and let <span><math><msub><mrow><mo>(</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>)</mo></mrow><mrow><mi>t</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></msub></math></span> be the associated conditional expectations. We prove in the present paper that if the symmetric space <span><math><mi>E</mi><mo>∈</mo><mi>Int</mi><mo>[</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>]</mo></math></span> with <span><math><mn>1</mn><mo><</mo><mi>p</mi><mo>≤</mo><mi>q</mi><mo><</mo><mn>2</mn></math></span> and <em>E</em> is <span><math><mn>2</mn><mo>(</mo><mn>1</mn><mo>−</mo><mi>θ</mi><mo>)</mo></math></span>-convex and <em>w</em>-concave with <span><math><mi>p</mi><mo><</mo><mi>w</mi><mo><</mo><mn>2</mn></math></span>, then the following holds:<span><span><span><math><msub><mrow><mo>‖</mo><msub><mrow><mo>(</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></mrow><mrow><mi>t</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></msub><mo>‖</mo></mrow><mrow><mi>E</mi><mo>(</mo><mi>M</mi><mo>;</mo><msubsup><mrow><mi>ℓ</mi></mrow><mrow><mo>∞</mo></mrow><mrow><mi>θ</mi></mrow></msubsup><mo>)</mo></mrow></msub><mo>≤</mo><msub><mrow><mi>C</mi></mrow><mrow><mi>E</mi><mo>,</mo><mi>θ</mi></mrow></msub><msub><mrow><mo>‖</mo><mi>x</mi><mo>‖</mo></mrow><mrow><msubsup><mrow><mi>H</mi></mrow><mrow><mi>E</mi></mrow><mrow><mi>c</mi></mrow></msubsup></mrow></msub><mo>,</mo><mspace></mspace><mi>x</mi><mo>∈</mo><msubsup><mrow><mi>H</mi></mrow><mrow><mi>E</mi></mrow><mrow><mi>c</mi></mrow></msubsup><mo>(</mo><mi>M</mi><mo>)</mo></math></span></span></span> provided <span><math><mn>1</mn><mo>−</mo><mi>p</mi><mo>/</mo><mn>2</mn><mo><</mo><mi>θ</mi><mo><</mo><mn>1</mn></math></span>. Similar result holds for <span><math><mi>x</mi><mo>∈</mo><msubsup><mrow><mi>H</mi></mrow><mrow><mi>E</mi></mrow><mrow><mi>r</mi></mrow></msubsup><mo>(</mo><mi>M</mi><mo>)</mo></math></span>. Moreover, if <span><math><mi>E</mi><mo>∈</mo><mi>Int</mi><mo>[</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>]</mo></math></span> with <span><math><mn>1</mn><mo><</mo><mi>p</mi><mo>≤</mo><mi>q</mi><mo><</mo><mn>2</mn></math></span> and <em>E</em> is <em>w</em>-concave with <span><math><mn>2</
让(M,τ)是一个非交换概率空间,配备了一个滤波 (Mt)t∈[0,1],其联合在 M 中是 w⁎密集的;让 (Et)t∈[0,1] 是相关的条件期望。本文将证明,如果对称空间 E∈Int[Lp,Lq]为 1<p≤q<2,且 E 为 2(1-θ)-convex 和 w-concave 为 p<w<2,则以下条件成立:Et(x))t∈[0,1]‖E(M;ℓ∞θ)≤CE,θ‖x‖HEc,x∈HEc(M)提供 1-p/2<;θ<;1。类似的结果也适用于 x∈HEr(M)。此外,如果 E∈Int[Lp,Lq]为 1<p≤q<2,且 E 为 w-concave with 2<w<;2p/(2-p),则对于每个 x∈E(M)存在 y、z∈E(M),使得 x=y+z 且‖(Et(y))t∈[0,1]‖E(M;ℓ∞c)+‖(Et(z))t∈[0,1]‖E(M;ℓ∞r)≤c‖Ex‖E(M)。这些结果可视为 Randrianantoanina 等人[33]的连续类似结果。我们证明的关键要素之一是一般对称空间 E 的 E(M)模块的新分解定理,它扩展了 Junge 和 Sherman 的已知结果。
{"title":"Continuous asymmetric Doob inequalities in noncommutative symmetric spaces","authors":"Yong Jiao, Hui Li, Sijie Luo, Lian Wu","doi":"10.1016/j.jfa.2024.110701","DOIUrl":"10.1016/j.jfa.2024.110701","url":null,"abstract":"<div><div>Let <span><math><mo>(</mo><mi>M</mi><mo>,</mo><mi>τ</mi><mo>)</mo></math></span> be a noncommutative probability space equipped with a filtration <span><math><msub><mrow><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>)</mo></mrow><mrow><mi>t</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></msub></math></span> whose union is <span><math><msup><mrow><mi>w</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>-dense in <span><math><mi>M</mi></math></span>, and let <span><math><msub><mrow><mo>(</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>)</mo></mrow><mrow><mi>t</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></msub></math></span> be the associated conditional expectations. We prove in the present paper that if the symmetric space <span><math><mi>E</mi><mo>∈</mo><mi>Int</mi><mo>[</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>]</mo></math></span> with <span><math><mn>1</mn><mo><</mo><mi>p</mi><mo>≤</mo><mi>q</mi><mo><</mo><mn>2</mn></math></span> and <em>E</em> is <span><math><mn>2</mn><mo>(</mo><mn>1</mn><mo>−</mo><mi>θ</mi><mo>)</mo></math></span>-convex and <em>w</em>-concave with <span><math><mi>p</mi><mo><</mo><mi>w</mi><mo><</mo><mn>2</mn></math></span>, then the following holds:<span><span><span><math><msub><mrow><mo>‖</mo><msub><mrow><mo>(</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo><mo>)</mo></mrow><mrow><mi>t</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></msub><mo>‖</mo></mrow><mrow><mi>E</mi><mo>(</mo><mi>M</mi><mo>;</mo><msubsup><mrow><mi>ℓ</mi></mrow><mrow><mo>∞</mo></mrow><mrow><mi>θ</mi></mrow></msubsup><mo>)</mo></mrow></msub><mo>≤</mo><msub><mrow><mi>C</mi></mrow><mrow><mi>E</mi><mo>,</mo><mi>θ</mi></mrow></msub><msub><mrow><mo>‖</mo><mi>x</mi><mo>‖</mo></mrow><mrow><msubsup><mrow><mi>H</mi></mrow><mrow><mi>E</mi></mrow><mrow><mi>c</mi></mrow></msubsup></mrow></msub><mo>,</mo><mspace></mspace><mi>x</mi><mo>∈</mo><msubsup><mrow><mi>H</mi></mrow><mrow><mi>E</mi></mrow><mrow><mi>c</mi></mrow></msubsup><mo>(</mo><mi>M</mi><mo>)</mo></math></span></span></span> provided <span><math><mn>1</mn><mo>−</mo><mi>p</mi><mo>/</mo><mn>2</mn><mo><</mo><mi>θ</mi><mo><</mo><mn>1</mn></math></span>. Similar result holds for <span><math><mi>x</mi><mo>∈</mo><msubsup><mrow><mi>H</mi></mrow><mrow><mi>E</mi></mrow><mrow><mi>r</mi></mrow></msubsup><mo>(</mo><mi>M</mi><mo>)</mo></math></span>. Moreover, if <span><math><mi>E</mi><mo>∈</mo><mi>Int</mi><mo>[</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>]</mo></math></span> with <span><math><mn>1</mn><mo><</mo><mi>p</mi><mo>≤</mo><mi>q</mi><mo><</mo><mn>2</mn></math></span> and <em>E</em> is <em>w</em>-concave with <span><math><mn>2</","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110701"},"PeriodicalIF":1.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.jfa.2024.110700
Yong Jiao, Sijie Luo, Dejian Zhou
In the present paper, we use the semigroup method to investigate various functional inequalities invoking and norms in the framework of canonical anti-commuting relations algebra (CAR algebra for short). As the main results, we obtain the Poincaré inequality for Talagrand type sum, Eldan-Gross inequality for projections, and the Talagrand influence inequality along with its strengthening form in the CAR algebra. All our results strengthen the noncommutative Poincaré inequality of Efraim and Lust-Piquard at several points. We conclude the paper with two applications of our inequalities. In the first application, we apply the noncommutative Eldan-Gross inequality to derive two KKL-type inequalities in the CAR algebra, which are closely related to the quantum KKL conjecture of Montanaro and Osborne. The second application is the CAR algebra counterpart of the superconcentration phenomenon derived from the noncommutative Talagrand influence inequality.
在本文中,我们使用半群方法研究了在典型反交换关系代数(简称 CAR 代数)框架内援引 L1 和 Lp 准则的各种函数不等式。作为主要结果,我们得到了塔拉格兰德型和的庞加莱不等式、投影的埃尔丹-格罗斯不等式和塔拉格兰德影响不等式及其在 CAR 代数中的加强形式。我们的所有结果都在若干点上加强了埃弗拉伊姆和卢斯特-皮夸德的非交换泊恩卡雷不等式。最后,我们以两个不等式的应用来结束本文。在第一个应用中,我们应用非交换埃尔丹-格罗斯不等式推导出 CAR 代数中的两个 KKL 型不等式,它们与蒙塔纳罗和奥斯本的量子 KKL 猜想密切相关。第二个应用是非交换塔拉格朗影响不等式推导出的 CAR 代数对应的超集中现象。
{"title":"Functional L1-Lp inequalities in the CAR algebra","authors":"Yong Jiao, Sijie Luo, Dejian Zhou","doi":"10.1016/j.jfa.2024.110700","DOIUrl":"10.1016/j.jfa.2024.110700","url":null,"abstract":"<div><div>In the present paper, we use the semigroup method to investigate various functional inequalities invoking <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> norms in the framework of canonical anti-commuting relations algebra (CAR algebra for short). As the main results, we obtain the Poincaré inequality for Talagrand type sum, Eldan-Gross inequality for projections, and the Talagrand influence inequality along with its strengthening form in the CAR algebra. All our results strengthen the noncommutative Poincaré inequality of Efraim and Lust-Piquard at several points. We conclude the paper with two applications of our inequalities. In the first application, we apply the noncommutative Eldan-Gross inequality to derive two KKL-type inequalities in the CAR algebra, which are closely related to the quantum KKL conjecture of Montanaro and Osborne. The second application is the CAR algebra counterpart of the superconcentration phenomenon derived from the noncommutative Talagrand influence inequality.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110700"},"PeriodicalIF":1.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.jfa.2024.110702
Miho Mukohara
Inclusions of operator algebras have long been studied. In particular, inclusions arising from actions of compact groups on factors were studied by Izumi-Longo-Popa and others. The correspondence between intermediate subfactors and subgroups is called the Galois correspondence. Analogues for actions on C⁎-algebras have been studied by Izumi, Cameron-Smith, Peligrad, and others. In this article, we give examples of compact group actions on simple C⁎-algebras for which the Galois correspondence holds.
{"title":"Inclusions of simple C⁎-algebras arising from compact group actions","authors":"Miho Mukohara","doi":"10.1016/j.jfa.2024.110702","DOIUrl":"10.1016/j.jfa.2024.110702","url":null,"abstract":"<div><div>Inclusions of operator algebras have long been studied. In particular, inclusions arising from actions of compact groups on factors were studied by Izumi-Longo-Popa and others. The correspondence between intermediate subfactors and subgroups is called the Galois correspondence. Analogues for actions on C<sup>⁎</sup>-algebras have been studied by Izumi, Cameron-Smith, Peligrad, and others. In this article, we give examples of compact group actions on simple C<sup>⁎</sup>-algebras for which the Galois correspondence holds.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110702"},"PeriodicalIF":1.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.jfa.2024.110698
Petr Hájek
Let be a Banach space such that all -convergent sequences in the dual unit sphere are also norm convergent. Then the weak⁎ and norm topologies agree on . By known results it implies that X has a renorming whose dual is locally uniformly rotund, hence also -Fréchet smooth. In particular, X is an Asplund space. Our results also lend an alternative proof of the celebrated Josefson-Nissenzweig theorem.
设(X,‖⋅‖)是一个巴拿赫空间,其对偶单位球 SX⁎中所有 w⁎ 收敛序列也是规范收敛的。那么弱⁎拓扑和规范拓扑在 SX⁎上是一致的。根据已知结果,这意味着 X 有一个重重整,其对偶是局部均匀旋转的,因此也是 C1-弗雷谢特光滑的。特别是,X 是一个阿斯普朗德空间。我们的结果还为著名的约瑟夫森-尼森茨威格定理提供了另一种证明。
{"title":"On dual Kadec norms","authors":"Petr Hájek","doi":"10.1016/j.jfa.2024.110698","DOIUrl":"10.1016/j.jfa.2024.110698","url":null,"abstract":"<div><div>Let <span><math><mo>(</mo><mi>X</mi><mo>,</mo><mo>‖</mo><mo>⋅</mo><mo>‖</mo><mo>)</mo></math></span> be a Banach space such that all <span><math><msup><mrow><mi>w</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>-convergent sequences in the dual unit sphere <span><math><msub><mrow><mi>S</mi></mrow><mrow><msup><mrow><mi>X</mi></mrow><mrow><mo>⁎</mo></mrow></msup></mrow></msub></math></span> are also norm convergent. Then the weak<sup>⁎</sup> and norm topologies agree on <span><math><msub><mrow><mi>S</mi></mrow><mrow><msup><mrow><mi>X</mi></mrow><mrow><mo>⁎</mo></mrow></msup></mrow></msub></math></span>. By known results it implies that <em>X</em> has a renorming whose dual is locally uniformly rotund, hence also <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span>-Fréchet smooth. In particular, <em>X</em> is an Asplund space. Our results also lend an alternative proof of the celebrated Josefson-Nissenzweig theorem.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 1","pages":"Article 110698"},"PeriodicalIF":1.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.jfa.2024.110699
Anna Duwenig , Boyu Li
We introduce the notion of self-similar actions of groupoids on other groupoids and Fell bundles. This leads to a new imprimitivity theorem arising from such dynamics, generalizing many earlier imprimitivity theorems involving group and groupoid actions.
{"title":"Imprimitivity theorems and self-similar actions on Fell bundles","authors":"Anna Duwenig , Boyu Li","doi":"10.1016/j.jfa.2024.110699","DOIUrl":"10.1016/j.jfa.2024.110699","url":null,"abstract":"<div><div>We introduce the notion of self-similar actions of groupoids on other groupoids and Fell bundles. This leads to a new imprimitivity theorem arising from such dynamics, generalizing many earlier imprimitivity theorems involving group and groupoid actions.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"288 2","pages":"Article 110699"},"PeriodicalIF":1.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}