{"title":"Vector-Valued Singular Integrals on Locally Doubling Spaces","authors":"Mattia Calzi, Elena Rizzo","doi":"10.1007/s10455-026-10055-2","DOIUrl":"10.1007/s10455-026-10055-2","url":null,"abstract":"<div><p>We prove vector-valued boundedness of (suitable) Calderón-Zygmund operators and of the (truncated) Hardy–Littlewood maximal function on a <i>connected</i> locally doubling metric measure space.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 2","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751441","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}
{"title":"Some rigidity results for static three-manifolds with boundary and positive scalar curvature","authors":"Vladimir Medvedev","doi":"10.1007/s10455-026-10056-1","DOIUrl":"10.1007/s10455-026-10056-1","url":null,"abstract":"<div><p>This paper studies three-dimensional compact static manifolds with boundary and positive scalar curvature. We prove that, under a suitable bound on the Ricci curvature, the orientable quotient of the Nariai static manifold with boundary <span>(Nar_{-1,1}(mathbb {S}^2))</span> is the only such manifold with connected boundary, provided that the zero-level set of the potential is connected and does not intersect the boundary. We also establish a rigidity theorem for the upper hemisphere with the standard static potential, in the spirit of Cruz and Nunes.\u0000</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 2","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750985","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}
{"title":"On compact solvmanifolds with left-invariant complex structures","authors":"Takumi Yamada","doi":"10.1007/s10455-026-10053-4","DOIUrl":"10.1007/s10455-026-10053-4","url":null,"abstract":"<div><p>We investigate complex geometric properties of compact complex solvmanifolds endowed with left-invariant complex structures, focusing on the case where these manifolds admit a complex parallelizable solvmanifold as a finite covering. While our previous paper examined differences among complex solvmanifolds admitting a common complex parallelizable solvmanifold as a finite covering, the present paper is devoted to the study of their common geometric properties.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 2","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614034","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}
{"title":"A Willmore-type inequality for hypersurfaces with asymptotic or integral Ricci curvature bounds","authors":"Jihye Lee","doi":"10.1007/s10455-026-10054-3","DOIUrl":"10.1007/s10455-026-10054-3","url":null,"abstract":"<div><p>We establish Willmore-type inequalities for bounded domains in complete non-compact Riemannian manifolds, under either asymptotic or integral Ricci curvature bounds. Those results recover a recent inequality of Jin-Yin [12, Theorem 1.3].</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 2","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10455-026-10054-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crowned Lie groups and nets of real subspaces","authors":"Daniel Beltiţă, Karl-Hermann Neeb","doi":"10.1007/s10455-026-10052-5","DOIUrl":"10.1007/s10455-026-10052-5","url":null,"abstract":"<div><p>We introduce the notion of a complex crown domain for a connected Lie group <i>G</i>, and we use analytic extensions of orbit maps of antiunitary representations to these domains to construct nets of real subspaces on <i>G</i> that are isotone, covariant and satisfy the Reeh–Schlieder and Bisognano–Wichmann conditions from Algebraic Quantum Field Theory. This provides a unifying perspective on various constructions of such nets. The representation theoretic properties of different crowns are discussed in some detail for the non-abelian 2-dimensional Lie group <span>(mathop {textrm{Aff}}nolimits ({mathbb R}))</span>. We also characterize the existence of nets with the above properties by a regularity condition in terms of an Euler element in the Lie algebra <span>({mathfrak g})</span> and show that all antiunitary representations of the split oscillator group have this property.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 2","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148389038","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}
{"title":"Semi-Riemannian (text {spin}^c) manifolds carrying generalized Killing spinors and the classification of Riemannian (text {spin}^c) manifolds admitting a type I imaginary generalized Killing spinor","authors":"Samuel Lockman","doi":"10.1007/s10455-026-10051-6","DOIUrl":"10.1007/s10455-026-10051-6","url":null,"abstract":"<div><p>We classify Riemannian <span>(text {spin}^c)</span> manifolds carrying a type I imaginary generalized Killing spinor, by explicitly constructing a parallel spinor on each leaf of the canonical foliation given by the Dirac current. We also provide a class of Riemannian <span>(text {spin}^c)</span> manifolds carrying a type II imaginary generalized Killing spinor, by considering spacelike hypersurfaces of Lorentzian <span>(text {spin}^c)</span> manifolds. We carry out much of the work in the setting of semi-Riemannian <span>(text {spin}^c)</span>-manifolds carrying generalized Killing spinors, allowing us to draw conclusions in this setting as well. In this context, the Dirac current is not always a closed vector field. We circumvent this in even dimensions, by considering a modified Dirac current, which is closed in the cases when the original Dirac current is not. On the path to these results, we also study semi-Riemannian manifolds carrying closed and conformal vector fields.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10455-026-10051-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148323073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Aubin-Yau theorem for transversally Kähler foliations","authors":"Vlad Marchidanu","doi":"10.1007/s10455-026-10049-0","DOIUrl":"10.1007/s10455-026-10049-0","url":null,"abstract":"<div><p>Transversally Kähler foliations are a generalisation of Kähler manifolds, appearing naturally in the complex non-Kähler setting. We give a self-contained proof of how the classical methods used in the proof of the Aubin-Yau theorem adapt to the transversally Kähler case under the homological orientability condition. We apply this result to obtain a new, simpler proof of the already known Vaisman Aubin-Yau theorem.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10455-026-10049-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148281362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giulio Colombo, Filippo Mastropietro, Marco Rigoli
{"title":"On the Geometry of Cotton Gravity","authors":"Giulio Colombo, Filippo Mastropietro, Marco Rigoli","doi":"10.1007/s10455-026-10048-1","DOIUrl":"10.1007/s10455-026-10048-1","url":null,"abstract":"<div><p>We analyze the geometry of the field equations of Cotton gravity (for a quite general energy-momentum tensor) on a static space-time. In particular, we describe the local structure of the spatial Riemannian factor. This structure, that we call <i>Cotton-</i><span>(varphi )</span><i>-perfect fluid</i> (C-<span>(varphi )</span>-PF, for shorts) is a generalization to the regime of Cotton Gravity of the recently introduced notion of <span>(varphi )</span>-static perfect fluid space-time (<span>(varphi )</span>-SPFST). After discussing the variational origin of this system, we provide sufficient conditions for a C-<span>(varphi )</span>-PF to reduce to a <span>(varphi )</span>-SPFST. We also study the geometry of the level sets of the lapse function <i>f</i> and we provide a rigidity result for C-<span>(varphi )</span>-PFs under some curvature conditions. The role that Codazzi tensors hold in this theory is highlighted.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148193856","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}
{"title":"Real hypersurfaces with cyclic parallel normal Jacobi operator in non-flat quaternionic space forms","authors":"Jin Hong Kim, Hyunjin Lee, Young Jin Suh","doi":"10.1007/s10455-026-10042-7","DOIUrl":"10.1007/s10455-026-10042-7","url":null,"abstract":"<div><p>In this paper, we investigate the properties of the normal Jacobi operator of a real hypersurface in non-flat quaternionic space forms, focused on cyclic parallelism and Codazzi type properties. We classify real hypersurfaces that satisfy these properties. As a solution of the classification problem for such real hypersurfaces, we present the following results: Firstly, we prove that a real hypersurface satisfying a certain condition for the normal Jacobi operator is curvature-adapted. Based on this fact, we further show that in the quaternionic hyperbolic space, the shape operator <i>A</i> of <i>M</i> commutes with the three structure tensors <span>(phi _{nu })</span>, <span>(nu =1,2,3)</span>, of <i>M</i> on the maximal quaternionic subbundle <span>(mathfrak D)</span>.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"70 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148193857","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}
{"title":"Remarks on quasi-Sasakian structures","authors":"Emmanuel Gnandi, Fortuné Massamba","doi":"10.1007/s10455-026-10047-2","DOIUrl":"10.1007/s10455-026-10047-2","url":null,"abstract":"<div><p>In this work, we revisit quasi-Sasakian structures in dimension three and examine how these structures interact with the foliation generated by the Reeb vector field and its basic cohomology. Through a deformation-based approach, we show that a closed, orientable 3-manifold admits a quasi-Sasakian structure precisely when it is either Sasakian or arises as a Kähler mapping torus. In particular, every quasi-Sasakian structure in this setting can be deformed into a Sasakian or a co-Kähler one. This result leads to a complete classification of quasi-Sasakian manifolds in dimension three and highlights the geometric and topological features that distinguish the two cases.</p></div>","PeriodicalId":8268,"journal":{"name":"Annals of Global Analysis and Geometry","volume":"69 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148172161","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}