{"title":"The constraint tensor for null hypersurfaces","authors":"Miguel Manzano, Marc Mars","doi":"10.1016/j.geomphys.2024.105375","DOIUrl":null,"url":null,"abstract":"<div><div>In this work we provide a definition of the constraint tensor of a null hypersurface data which is completely explicit in the extrinsic geometry of the hypersurface. The definition is fully covariant and applies for any topology of the hypersurface. For data embedded in a spacetime, the constraint tensor coincides with the pull-back of the ambient Ricci tensor. As applications of the results, we find three geometric quantities on any transverse submanifold <em>S</em> of the data with remarkably simple gauge behaviour, and prove that the restriction of the constraint tensor to <em>S</em> takes a very simple form in terms of them. We also obtain an identity that generalizes the standard near horizon equation of isolated horizons to totally geodesic null hypersurfaces with any topology. Finally, we prove that when a null hypersurface has product topology, its extrinsic curvature can be uniquely reconstructed from the constraint tensor plus suitable initial data on a cross-section.</div></div>","PeriodicalId":55602,"journal":{"name":"Journal of Geometry and Physics","volume":"208 ","pages":"Article 105375"},"PeriodicalIF":1.6000,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geometry and Physics","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0393044024002766","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this work we provide a definition of the constraint tensor of a null hypersurface data which is completely explicit in the extrinsic geometry of the hypersurface. The definition is fully covariant and applies for any topology of the hypersurface. For data embedded in a spacetime, the constraint tensor coincides with the pull-back of the ambient Ricci tensor. As applications of the results, we find three geometric quantities on any transverse submanifold S of the data with remarkably simple gauge behaviour, and prove that the restriction of the constraint tensor to S takes a very simple form in terms of them. We also obtain an identity that generalizes the standard near horizon equation of isolated horizons to totally geodesic null hypersurfaces with any topology. Finally, we prove that when a null hypersurface has product topology, its extrinsic curvature can be uniquely reconstructed from the constraint tensor plus suitable initial data on a cross-section.
在这项工作中,我们给出了空超曲面数据的约束张量定义,该定义在超曲面的外几何学中是完全明确的。该定义是完全协变的,适用于超曲面的任何拓扑结构。对于嵌入时空的数据,约束张量与环境里奇张量的回拉重合。作为结果的应用,我们在数据的任意横向子满面 S 上发现了三个几何量,它们具有非常简单的轨距行为,并证明了约束张量对 S 的限制采用了非常简单的形式。我们还得到了一个特性,它将孤立地平线的标准近地平线方程推广到具有任意拓扑结构的完全大地空超曲面。最后,我们证明了当空超曲面具有积拓扑结构时,其外曲率可以通过约束张量加上横截面上合适的初始数据唯一地重建。
期刊介绍:
The Journal of Geometry and Physics is an International Journal in Mathematical Physics. The Journal stimulates the interaction between geometry and physics by publishing primary research, feature and review articles which are of common interest to practitioners in both fields.
The Journal of Geometry and Physics now also accepts Letters, allowing for rapid dissemination of outstanding results in the field of geometry and physics. Letters should not exceed a maximum of five printed journal pages (or contain a maximum of 5000 words) and should contain novel, cutting edge results that are of broad interest to the mathematical physics community. Only Letters which are expected to make a significant addition to the literature in the field will be considered.
The Journal covers the following areas of research:
Methods of:
• Algebraic and Differential Topology
• Algebraic Geometry
• Real and Complex Differential Geometry
• Riemannian Manifolds
• Symplectic Geometry
• Global Analysis, Analysis on Manifolds
• Geometric Theory of Differential Equations
• Geometric Control Theory
• Lie Groups and Lie Algebras
• Supermanifolds and Supergroups
• Discrete Geometry
• Spinors and Twistors
Applications to:
• Strings and Superstrings
• Noncommutative Topology and Geometry
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• Geometry Approaches to Thermodynamics
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• Classical and Quantum Mechanics
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