{"title":"Curvature exponent and geodesic dimension on Sard-regular Carnot groups","authors":"Sebastiano Nicolussi Golo, Ye Zhang","doi":"10.1515/agms-2024-0004","DOIUrl":null,"url":null,"abstract":"In this study, we characterize the geodesic dimension <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_agms-2024-0004_eq_001.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mrow> <m:mi>N</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant=\"normal\">GEO</m:mi> </m:mrow> </m:msub> </m:math> <jats:tex-math>{N}_{{\\rm{GEO}}}</jats:tex-math> </jats:alternatives> </jats:inline-formula> and give a new lower bound to the curvature exponent <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_agms-2024-0004_eq_002.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mrow> <m:mi>N</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant=\"normal\">CE</m:mi> </m:mrow> </m:msub> </m:math> <jats:tex-math>{N}_{{\\rm{CE}}}</jats:tex-math> </jats:alternatives> </jats:inline-formula> on Sard-regular Carnot groups. As an application, we give an example of step-two Carnot group on which <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_agms-2024-0004_eq_003.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msub> <m:mrow> <m:mi>N</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant=\"normal\">CE</m:mi> </m:mrow> </m:msub> <m:mo>></m:mo> <m:msub> <m:mrow> <m:mi>N</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant=\"normal\">GEO</m:mi> </m:mrow> </m:msub> </m:math> <jats:tex-math>{N}_{{\\rm{CE}}}\\gt {N}_{{\\rm{GEO}}}</jats:tex-math> </jats:alternatives> </jats:inline-formula>; this answers a question posed by Rizzi (<jats:italic>Measure contraction properties of Carnot groups</jats:italic>. Calc. Var. Partial Differential Equations 55 (2016), no. 3, Art. 60, 20).","PeriodicalId":48637,"journal":{"name":"Analysis and Geometry in Metric Spaces","volume":"13 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Analysis and Geometry in Metric Spaces","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1515/agms-2024-0004","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this study, we characterize the geodesic dimension NGEO{N}_{{\rm{GEO}}} and give a new lower bound to the curvature exponent NCE{N}_{{\rm{CE}}} on Sard-regular Carnot groups. As an application, we give an example of step-two Carnot group on which NCE>NGEO{N}_{{\rm{CE}}}\gt {N}_{{\rm{GEO}}}; this answers a question posed by Rizzi (Measure contraction properties of Carnot groups. Calc. Var. Partial Differential Equations 55 (2016), no. 3, Art. 60, 20).
在本研究中,我们描述了测地维 N GEO {N}_{\rm{GEO}} 的特征,并给出了沙特规则卡诺群上曲率指数 N CE {N}_{\rm{CE}} 的新下限。作为应用,我们给出了一个阶二卡诺群的例子,其中 N CE > N GEO {N}_{{\rm{CE}}}\gt {N}_{{\rm{GEO}}} ;这回答了里齐提出的一个问题(卡诺群的度量收缩性质.Calc.Calc.Partial Differential Equations 55 (2016), no.3, Art.60, 20).
期刊介绍:
Analysis and Geometry in Metric Spaces is an open access electronic journal that publishes cutting-edge research on analytical and geometrical problems in metric spaces and applications. We strive to present a forum where all aspects of these problems can be discussed.
AGMS is devoted to the publication of results on these and related topics:
Geometric inequalities in metric spaces,
Geometric measure theory and variational problems in metric spaces,
Analytic and geometric problems in metric measure spaces, probability spaces, and manifolds with density,
Analytic and geometric problems in sub-riemannian manifolds, Carnot groups, and pseudo-hermitian manifolds.
Geometric control theory,
Curvature in metric and length spaces,
Geometric group theory,
Harmonic Analysis. Potential theory,
Mass transportation problems,
Quasiconformal and quasiregular mappings. Quasiconformal geometry,
PDEs associated to analytic and geometric problems in metric spaces.