{"title":"A view from above on JNp(Rn)","authors":"Shahaboddin Shaabani","doi":"10.1016/j.jfa.2025.111235","DOIUrl":"10.1016/j.jfa.2025.111235","url":null,"abstract":"<div><div>For a symmetric convex body <span><math><mi>K</mi><mo>⊂</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span> and <span><math><mn>1</mn><mo>≤</mo><mi>p</mi><mo><</mo><mo>∞</mo></math></span>, we define the space <span><math><msup><mrow><mi>S</mi></mrow><mrow><mi>p</mi></mrow></msup><mo>(</mo><mi>K</mi><mo>)</mo></math></span> to be the tent generalization of <span><math><msub><mrow><mtext>JN</mtext></mrow><mrow><mi>p</mi></mrow></msub><mo>(</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>)</mo></math></span>, i.e., the space of all continuous functions <em>f</em> on the upper-half space <span><math><msubsup><mrow><mi>R</mi></mrow><mrow><mo>+</mo></mrow><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow></msubsup></math></span> such that<span><span><span><math><msub><mrow><mo>‖</mo><mi>f</mi><mo>‖</mo></mrow><mrow><msup><mrow><mi>S</mi></mrow><mrow><mi>p</mi></mrow></msup><mo>(</mo><mi>K</mi><mo>)</mo></mrow></msub><mo>:</mo><mo>=</mo><msup><mrow><mo>(</mo><munder><mi>sup</mi><mrow><mi>C</mi></mrow></munder><mo></mo><munder><mo>∑</mo><mrow><mi>B</mi><mo>∈</mo><mi>C</mi></mrow></munder><mo>|</mo><msub><mrow><mi>f</mi></mrow><mrow><mi>B</mi></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mi>p</mi></mrow></msup><mo>)</mo></mrow><mrow><mfrac><mrow><mn>1</mn></mrow><mrow><mi>p</mi></mrow></mfrac></mrow></msup><mo><</mo><mo>∞</mo><mo>,</mo></math></span></span></span> where, in the above, the supremum is taken over all finite disjoint collections of homothetic copies of <em>K</em>. It is then shown that the dual of <span><math><msubsup><mrow><mi>S</mi></mrow><mrow><mn>0</mn></mrow><mrow><mn>1</mn></mrow></msubsup><mo>(</mo><mi>K</mi><mo>)</mo></math></span>, the closure of the space of continuous functions with compact support in <span><math><msup><mrow><mi>S</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>K</mi><mo>)</mo></math></span>, consists of all Radon measures on <span><math><msubsup><mrow><mi>R</mi></mrow><mrow><mo>+</mo></mrow><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow></msubsup></math></span> with uniformly bounded total variation on cones with base <em>K</em> and vertex in <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span>. In addition, a similar scale of spaces is defined in the dyadic setting, and for <span><math><mn>1</mn><mo>≤</mo><mi>p</mi><mo><</mo><mo>∞</mo></math></span>, a complete characterization of their duals is given. We apply our results to study dyadic <span><math><msub><mrow><mtext>JN</mtext></mrow><mrow><mi>p</mi></mrow></msub></math></span> spaces.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 3","pages":"Article 111235"},"PeriodicalIF":1.6,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145290177","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}
{"title":"Quantization and reduction for torsion free CR manifolds","authors":"Andrea Galasso , Chin-Yu Hsiao","doi":"10.1016/j.jfa.2025.111225","DOIUrl":"10.1016/j.jfa.2025.111225","url":null,"abstract":"<div><div>Consider a compact torsion free CR manifold <em>X</em> and assume that <em>X</em> admits a compact CR Lie group action <em>G</em>. Let <em>L</em> be a <em>G</em>-equivariant rigid CR line bundle over <em>X</em>. It seems natural to consider the space of <em>G</em>-invariant CR sections in the high tensor powers as quantization space, on which a certain weighted <em>G</em>-invariant Fourier–Szegő operator projects. Under certain natural assumptions, we show that the group invariant Fourier–Szegő projector admits a full asymptotic expansion. As an application, if the tensor power of the line bundle is large enough, we prove that quantization commutes with reduction.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 2","pages":"Article 111225"},"PeriodicalIF":1.6,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269296","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}
{"title":"Turning point principle for the stability of viscous gaseous stars","authors":"Ming Cheng , Zhiwu Lin , Yucong Wang","doi":"10.1016/j.jfa.2025.111239","DOIUrl":"10.1016/j.jfa.2025.111239","url":null,"abstract":"<div><div>We investigate the stability of non-rotating viscous gaseous stars, which are modeled by the Navier-Stokes-Poisson system. Based on general hypotheses concerning the equation of states, we demonstrate that the count of unstable modes in the linearized Navier-Stokes-Poisson system matches that of the linearized Euler-Poisson system modeling inviscid gaseous stars. In particular, the turning point principle holds for the non-rotating stars with viscosity. This principle asserts that the stability of these stars is determined by the mass-radius curve parameterized by the center density. The transition of stability only occurs at the extrema of the total mass. To substantiate our claims, we formulate an infinite-dimensional Kelvin-Tait-Chetaev Theorem for a class of abstract second-order linear equations with dissipation. Moreover, we prove that linear stability implies nonlinear asymptotic stability and linear instability implies nonlinear instability for the Navier-Stokes-Poisson system under spherically symmetric perturbations.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 3","pages":"Article 111239"},"PeriodicalIF":1.6,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145290178","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}
{"title":"Voiculescu's theorem in properly infinite factors","authors":"Donald Hadwin , Minghui Ma , Junhao Shen","doi":"10.1016/j.jfa.2025.111198","DOIUrl":"10.1016/j.jfa.2025.111198","url":null,"abstract":"<div><div>In this paper, we investigate Voiculescu's theorem on approximate unitary equivalence in separable properly infinite factors. As applications, we establish the norm-denseness of the set of all reducible operators, prove a generalized Voiculescu's bicommutant theorem and a version of asymptotic bicommutant theorem, and obtain an interesting cohomological result. Additionally, we extend these results to multiplier algebras within separable type III factors. At last, a concept of the nuclear length is introduced.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 1","pages":"Article 111198"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154381","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}
{"title":"On the converse of Prékopa's theorem and Berndtsson's theorem","authors":"Wang Xu , Hui Yang","doi":"10.1016/j.jfa.2025.111214","DOIUrl":"10.1016/j.jfa.2025.111214","url":null,"abstract":"<div><div>Extending the framework of the converse <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> theory, we establish converse results for Berndtsson's theorem on the plurisubharmonic variation of Bergman kernels, showing that both the plurisubharmonicity of functions and the pseudoconvexity of domains are necessary conditions in twisted senses. We also prove analogous results for Prékopa's theorem from convex analysis.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 1","pages":"Article 111214"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155322","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}
David A. Jekel , Todd A. Kemp , Evangelos A. Nikitopoulos
{"title":"A martingale approach to noncommutative stochastic calculus","authors":"David A. Jekel , Todd A. Kemp , Evangelos A. Nikitopoulos","doi":"10.1016/j.jfa.2025.111200","DOIUrl":"10.1016/j.jfa.2025.111200","url":null,"abstract":"<div><div>We present a new approach to noncommutative stochastic calculus that is, like the classical theory, based primarily on the martingale property. Using this approach, we introduce a general theory of stochastic integration and quadratic (co)variation for a certain class of noncommutative processes, analogous to semimartingales, that includes both the <em>q</em>-Brownian motions and classical matrix-valued Brownian motions. As applications, we obtain Burkholder–Davis–Gundy inequalities (with <span><math><mi>p</mi><mo>≥</mo><mn>2</mn></math></span>) for continuous-time noncommutative martingales and a noncommutative Itô's formula for “adapted <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> maps,” including trace ⁎-polynomial maps and operator functions associated to the noncommutative <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> scalar functions <span><math><mi>R</mi><mo>→</mo><mi>C</mi></math></span> introduced by Nikitopoulos, as well as the more general multivariate tracial noncommutative <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> functions introduced by Jekel, Li, and Shlyakhtenko.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 2","pages":"Article 111200"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222822","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}
{"title":"(INV) condition and regularity of the inverse","authors":"Anna Doležalová , Stanislav Hencl , Jani Onninen","doi":"10.1016/j.jfa.2025.111215","DOIUrl":"10.1016/j.jfa.2025.111215","url":null,"abstract":"<div><div>Let <span><math><mi>f</mi><mo>:</mo><mi>Ω</mi><mo>→</mo><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> be a Sobolev mapping of finite distortion between planar domains Ω and <span><math><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span>, satisfying the <span><math><mo>(</mo><mi>I</mi><mi>N</mi><mi>V</mi><mo>)</mo></math></span> condition and coinciding with a homeomorphism near ∂Ω. We show that <em>f</em> admits a generalized inverse mapping <span><math><mi>h</mi><mo>:</mo><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>→</mo><mi>Ω</mi></math></span>, which is also a Sobolev mapping of finite distortion and satisfies the <span><math><mo>(</mo><mi>I</mi><mi>N</mi><mi>V</mi><mo>)</mo></math></span> condition.</div><div>We also establish a higher-dimensional analogue of this result: if a mapping <span><math><mi>f</mi><mo>:</mo><mi>Ω</mi><mo>→</mo><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> of finite distortion is in the Sobolev class <span><math><msup><mrow><mi>W</mi></mrow><mrow><mn>1</mn><mo>,</mo><mi>p</mi></mrow></msup><mo>(</mo><mi>Ω</mi><mo>,</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>)</mo></math></span> with <span><math><mi>p</mi><mo>></mo><mi>n</mi><mo>−</mo><mn>1</mn></math></span> and satisfies the <span><math><mo>(</mo><mi>I</mi><mi>N</mi><mi>V</mi><mo>)</mo></math></span> condition, then <em>f</em> has an inverse in <span><math><msup><mrow><mi>W</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>1</mn></mrow></msup><mo>(</mo><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>,</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>)</mo></math></span> that is also of finite distortion.</div><div>Furthermore, we characterize Sobolev mappings satisfying <span><math><mo>(</mo><mi>I</mi><mi>N</mi><mi>V</mi><mo>)</mo></math></span> whose generalized inverses have finite <em>n</em>-harmonic energy.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 1","pages":"Article 111215"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155319","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}
{"title":"On the emergence of almost-honeycomb structures in low-energy planar clusters","authors":"M. Caroccia , K. DeMason , F. Maggi","doi":"10.1016/j.jfa.2025.111205","DOIUrl":"10.1016/j.jfa.2025.111205","url":null,"abstract":"<div><div>Several commonly observed physical and biological systems are arranged in shapes that closely resemble an honeycomb cluster, that is, a tessellation of the plane by regular hexagons. Although these shapes are not always the direct product of energy minimization, they can still be understood, at least phenomenologically, as low-energy configurations. In this paper, explicit quantitative estimates on the geometry of such low-energy configurations are provided, showing in particular that the vast majority of the chambers must be generalized polygons with six edges, and be closely resembling regular hexagons. Part of our arguments is a detailed revision of the estimates behind the global isoperimetric principle for honeycomb clusters due to Hales <span><span>[6]</span></span>.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 2","pages":"Article 111205"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157140","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}
{"title":"Nakano positivity of singular Hermitian metrics: Approximations and applications","authors":"Takahiro Inayama , Shin-ichi Matsumura","doi":"10.1016/j.jfa.2025.111206","DOIUrl":"10.1016/j.jfa.2025.111206","url":null,"abstract":"<div><div>This paper studies the approximation of singular Hermitian metrics on vector bundles using smooth Hermitian metrics with Nakano semi-positive curvature on Zariski open sets. We show that singular Hermitian metrics capable of this approximation satisfy Nakano semi-positivity as defined through the <span><math><mover><mrow><mo>∂</mo></mrow><mo>‾</mo></mover></math></span>-equation with optimal <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-estimates. Furthermore, for a projective fibration <span><math><mi>f</mi><mo>:</mo><mi>X</mi><mo>→</mo><mi>Y</mi></math></span> with a line bundle <em>L</em> on <em>X</em>, we provide a specific condition under which the <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-metric on the direct image sheaf <span><math><msub><mrow><mi>f</mi></mrow><mrow><mo>⁎</mo></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mi>X</mi></mrow></msub><mo>(</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>X</mi><mo>/</mo><mi>Y</mi></mrow></msub><mo>+</mo><mi>L</mi><mo>)</mo></math></span> admits this approximation. As an application, we establish several vanishing theorems.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 1","pages":"Article 111206"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118844","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}
{"title":"Minimal Lagrangian surfaces with Legendrian capillary boundary in S2×S2","authors":"Mingyan Li","doi":"10.1016/j.jfa.2025.111207","DOIUrl":"10.1016/j.jfa.2025.111207","url":null,"abstract":"<div><div>In this paper we study minimal Lagrangian surfaces in <span><math><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>×</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> with Legendrian capillary boundary on <span><math><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>×</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span>. We prove that such surfaces must be of annulus type and they are congruent to the totally geodesic Lagrangian torus.</div></div>","PeriodicalId":15750,"journal":{"name":"Journal of Functional Analysis","volume":"290 2","pages":"Article 111207"},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145134758","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}