內容簡介
《微分幾何中嘉當的活動標架法和外微分係統初步(英文版)》介紹瞭微分幾何的嘉當方法。嘉當幾何的兩個中心方法是外微分理論和活動標架方法,《微分幾何中嘉當的活動標架法和外微分係統初步(英文版)》對它們做瞭深入和現代化的處理,包括它們在古典和現代問題中的應用。
《微分幾何中嘉當的活動標架法和外微分係統初步(英文版)》一開始用活動標架的語言講述瞭經典麯麵幾何和基礎黎曼幾何,然後簡要介紹瞭外微分。很多關鍵概念是通過導嚮定義、定理和證明的有啓發性的例子逐步展開的。
這些方法的基礎建立後,作者便轉嚮應用和更高深的專題。一個引人注目的應用是關於復代數幾何的,在那裏射影微分幾何的一些重要結果得以拓展和更新。本書重點引進瞭G-結構並討論瞭聯絡理論。通過Darboux方法、特徵法、等價性的嘉當法,嘉當的這種機製也被用來求偏微分方程的顯式解。
《微分幾何中嘉當的活動標架法和外微分係統初步(英文版)》適閤在一年期的微分幾何研究生課程中講授,通篇包括大量的習題和例題。偏微分方程和代數幾何等方嚮的專傢如果想瞭解活動標架和外微分在他們領域中的應用,那麼本書對他們是十分有用的。
內頁插圖
目錄
Preface
Chapter 1. Moving Frames and Exterior Differential Systems
1.1. Geometry of surfaces in E3 in coordinates
1.2. Differential equations in coordinates
1.3. Introduction to differential equations without coordinates
1.4. Introduction to geometry without coordinates: curves in E2
1.5. Submanifolds of homogeneous spaces
1.6. The Maurer-Cartan form
1.7. Plane curves in other geometries
1.8. Curves in E3
1.9. Exterior differential systems and jet spaces
Chapter 2. Euclidean Geometry and Riemannian Geometry
2.1. Gauss and mean curvature via frames
2.2. Calculation of H and K for some examples
2.3. Darboux frames and applications
2.4. What do H and K tell us?
2.5. Invariants for n,-dimensional submanifolds of En+s
2.6. Intrinsic and extrinsic geometry
2.7. Space forms: the sphere and hyperbolic space
2.8. Curves on surfaces
2.9. The Gauss-Bonnet and Poincare-Hopf theorems
2.10. Non-orthonormalframes
Chapter 3. Projective Geometry
3.1. Grassmannians
3.2. Frames and the projective second fundamental form
3.3. Algebraic varieties
3.4. Varieties with degenerate Gauss mappings
3.5. Higher-order differential invariants
3.6. Fundamental forms of some homogeneous varieties
3.7. Higher-order Fubini forms
3.8. Ruled and uniruled varieties
3.9. Varieties with vanishing Fubini cubic
3.10. Dual varieties
3.11. Associated varieties
3.12. More on varieties with degenerate Gauss maps
3.13. Secant and tangential varieties
3.14. Rank restriction theorems
3.15. Local study of smooth varieties with degenerate tangential varieties
3.16. Generalized Monge systems
3.17. Complete intersections
Chapter 4. Cartan-Kahler Ⅰ: Linear Algebra and Constant-Coefficient Homogeneous Systems
4.1. Tableaux
4.2. First example
4.3. Second example
4.4. Third example
4.5. The general case
4.6. The characteristic variety of a tableau
Chapter 5. Cartan-Kahler Ⅱ: The Cartan Algorithm for Linear Pfaffian Systems
5.1. Linear Pfaffian systems
5.2. First example
5.3. Second example: constant coefficient homogeneous systems
5.4. The local isometric embedding problem
5.5. The Cartan algorithm formalized: tableau, torsion and prolongation
5.6. Summary of Cartan's algorithm for linear Pfaffian systems
5.7. Additional remarks on the theory
5.8. Examples
5.9. Functions whose Hessians commute, with remarks on singular solutions
5.10. The Cartan-Janet Isometric Embedding Theorem
5.11. Isometric embeddings of space forms (mostly flat ones)
5.12. Calibrated submanifolds
Chapter 6. Applications to PDE
6.1. Symmetries and Cauchy characteristics
6.2. Second-order PDE and Monge characteristics
6.3. Derived systems and the method of Darboux
6.4. Monge-Ampere systems and Weingarten surfaces
6.5. Integrable extensions and Backlund transformations
Chapter 7. Cartan-Kahler Ⅲ: The General Case
7.1. Integral elements and polar spaces
7.2. Example: Triply orthogonal systems
7.3. Statement and proof of Cartan-Kahler
7.4. Cartan's Test
7.5. More examples of Cartan's Test
Chapter 8. Geometric Structures and Connections
8.1. G-structures
8.2. How to differentiate sections of vector bundles
8.3. Connections on Fc and differential invariants of G-structures
8.4. Induced vector bundles and connections on induced bundles
8.5. Holonomy
8.6. Extended example: Path geometry
8.7. Frobenius and generalized conformal structures
Appendix A. Linear Algebra and Representation Theory
A.1. Dual spaces and tensor products
A.2. Matrix Lie groups
A.3. Complex vector spaces and complex structures
A.4. Lie algebras
A.5. Division algebras and the simple group G2
A.6. A smidgen of representation theory
A.7. Clifford algebras and spin groups
Appendix B. Differential Forms
B.1. Differential forms and vector fields
B.2. Three definitions of the exterior derivative
B.3. Basic and semi-basic forms
B.4. Differentialideals
Appendix C. Complex Structures and Complex Manifolds
C.1. Complex manifolds
C.2. The Cauchy-Riemann cquations
Appendix D. Initial Value Problems
Hints and Answers to Selected Exercises
Bibliography
Index
前言/序言
In this book, we use moving frames and exterior differential systems to study geometry and partial differential equations. These ideas originated about a century ago in the works of several mathematicians, including Gaston Darboux, Edouard Goursat and, most importantly, Elie Cartan. Over the years these techniques have been refined and extended; major contributors to the subject are mentioned below, under "Further Reading".
The book has the following features: It concisely covers the classical geometry of surfaces and basic Riemannian geometry in the language of moving frames. It includes results from projective differential geometry that update and expand the classic paper [69] of Griffiths and Harris. It provides an elementary introduction to the machinery of exterior differential systems (EDS), and an introduction to the basics of G-structures and the general theory of connections. Classical and recent geometric applications of these techniques are discussed throughout the text.
This book is intended to be used as a textbook for a graduate-level course; there are numerous exercises throughout. It is suitable for a one- year course, although it has more material than can be covered in a year, and parts of it are suitable for one-semester course (see the end of this preface for some suggestions). The intended audience is both graduate students who have some familiarity with classical differential geometry and differentiable manifolds, and experts in areas such as PDE and algebraic geometry who want to learn how moving frame and EDS techniques apply to their fields.
In addition to the geometric applications presented here, EDS techniques are also applied in CR geometry (see, e.g., [98]), robotics, and control theory (see [55, 56, 129]). This book prepares the reader for such areas, as well as for more advanced texts on exterior differential systems, such as [20], and papers on recent advances in the theory, such as [58, 117l. Overview. Each section begins with geometric examples and problems. Techniques and definitions are introduced when they become useful to help solve the geometric questions under discussion. We generally keep the pre- sentation elementary, although advanced topics are interspersed throughout the text.
In Chapter 1, we introduce moving frames via the geometry of curves in the Euclidean plane E2. We define the Maurer-Cartan form of a Lie group G and explain its use in the study of submanifolds of G-homogeneous spaces. We give additional examples, including the equivalence of holomorphic mappings up to fractional linear transformation, where the machinery leads one naturally to the Schwarzian derivative.
We define exterior differential systems and jet spaces, and explain how to rephrase any system of partial differential equations as an EDS using jets. We state and prove the Frobenius system, leading up to it via an elementary example of an overdetermined system of PDE.
In Chapter 2, we cover traditional material-the geometry of surfaces in three-dimensional Euclidean space, submanifolds of higher-dimensional Eu- clidean space, and the rudiments of Riemannian geometry-all using moving frames. Our emphasis is on local geometry, although we include standard global theorems such as the rigidity of the sphere and the Gauss-Bonnet Theorem. Our presentation emphasizes finding and interpreting differential invariants to enable the reader to use the same techniques in other settings.
We begin Chapter 3 with a discussion of Grassmannians and the Pliicker embedding. We present some well-known material (e.g., Fubini's theorem on the rigidity of the quadric) which is not readily available in other textbooks. We present several recent results, including the Zak and Landman theorems on the dual defect, and results of the second author on complete intersections. osculating hypersurfaces, uniruled varieties and varieties covered by lines. We keep the use of terminology and results from algebraic geometry to a minimum, but we believe we have included enough so that algebraic geometers will find this chapter useful.
好的,以下是根據您的要求撰寫的一份圖書簡介,重點圍繞微分幾何的基礎理論、李群、李代數以及外微分係統,同時避免提及您所提供的具體書名及內容。 --- 探索幾何的深度:從基礎概念到現代方法的解析 本書旨在為讀者提供一個深入而係統的幾何學探索之旅,重點聚焦於經典幾何框架下的關鍵概念及其在現代數學物理中的應用。我們旨在搭建一座堅實的橋梁,連接初學者對麯綫、麯麵幾何的直觀理解與高級研究中不可或缺的分析工具。全書結構嚴謹,邏輯清晰,力求在不犧牲數學嚴謹性的前提下,使得復雜概念易於消化吸收。 第一部分:基礎結構的重塑與概念的深化 本書的開篇部分將迴歸微分幾何的基石——流形(Manifolds)。我們將詳盡闡述拓撲空間、連續映射、微分結構等基本要素,為後續的微分幾何研究奠定堅實的基礎。我們不會止步於傳統的歐幾裏得空間,而是將視角擴展到抽象的微分流形上,探討如何在這個高維、非綫性的設定中定義光滑函數、嚮量場以及張量場。 嚮量場與切空間: 切空間作為流形上局部結構的核心,是理解方嚮和速度的關鍵。本書將深入剖析切空間的代數結構,並詳細闡述嚮量場如何構成一個李代數結構,這是後續研究李群理論的先決條件。我們將通過實例說明如何利用微分作用於函數(即李導數)來刻畫流形上的“運動”與“變形”。 微分形式與積分: 在本部分,我們將引入微分形式(Differential Forms)的概念,這是連接幾何直觀與代數計算的強大工具。從 0-形式(函數)到 $n$-形式(體積形式),我們將係統地構建外積代數(Exterior Algebra)。重點在於楔積(Wedge Product)的定義及其雙綫性、反對稱性質,這些性質是後續構建微分算子的核心。 微分算子與基本定理: 沿著外微分的路徑,我們將定義外微分(Exterior Derivative) $d$。這個運算將張量場的概念提升到瞭一個新的高度,使得我們可以用單一的代數操作來概括梯度、鏇度和散度等經典嚮量微積分概念。本書將深入探討著名的 Poincaré 引理(關於局部精確性)以及 Stokes 定理的推廣。這個推廣的 Stokes 定理將成為連接拓撲不變量與微分結構的核心工具,它清晰地展示瞭 $d^2 = 0$ 這一簡潔而深刻的代數關係在幾何中的物理意義。 第二部分:李群與李代數:對稱性的代數語言 現代幾何與物理學的核心支柱之一是對稱性的研究。本部分將引入李群(Lie Groups)的概念,它們是既是群又是光滑流形的結構,是描述連續對稱性的數學對象。 李群的結構: 我們將從歐幾裏得空間中的正交群 $O(n)$ 和特殊綫性群 $SL(n)$ 等經典例子入手,逐步抽象齣李群的定義。重點在於理解李群的局部結構——它在單位元附近的鄰域可以被一個嚮量空間所近似。 李代數的生成元: 這種局部近似導齣瞭李代數(Lie Algebra)的概念。李代數是與李群相關聯的切空間,其上的乘法運算被定義為李括號(Lie Bracket)。我們將詳盡地分析李括號的性質,特彆是它的反對稱性和雅可比恒等式。李括號不再僅僅是一個代數運算,而是衡量群結構“彎麯程度”的量度。 指數映射與對數映射: 連接群與代數的橋梁是指數映射。我們將詳細討論指數映射如何從李代數的元素映射到相應的李群元素,以及對數映射如何反之作用。這種映射關係使得我們可以利用代數工具(李代數)來分析拓撲和幾何結構(李群),這是解決許多微分幾何和拓撲問題的關鍵策略。 經典李群的分解: 本書將對 $GL(n), O(n), U(n)$ 等經典緊緻李群進行結構分析,探究它們的子群、根係(Root Systems)以及Cartan子代數(Cartan Subalgebras)的構造。理解這些代數結構,對於處理對稱空間和錶示論至關重要。 第三部分:構建解析工具:外微分係統導論 在掌握瞭流形和對稱性的代數工具之後,本書將進一步介紹一種強大的、基於微分形式的解析框架——外微分係統(Exterior Differential Systems)。這種方法為解決復雜的偏微分方程組以及研究微分方程的幾何結構提供瞭一種統一的視角。 微分形式的組閤與方程組: 我們將探討如何利用外微分係統來錶達一組耦閤的微分方程。一個外微分係統通常錶現為一個形式理想(Ideal of Forms)的集閤。重點在於理解什麼是“可積的”(Integrable)係統,即係統的解的存在性和唯一性條件。 Frobenius 定理的幾何詮釋: 係統的可積性在幾何上對應於 Frobenius 定理。我們將從高維微分形式的視角重新審視此定理,它明確指齣瞭何時一個由微分形式構成的子空間可以由一組獨立的函數或嚮量場的積分流來生成。這個定理是連接代數結構(外微分係統)與幾何構造(積分流形)的樞紐。 特徵值與解的存在性: 我們將分析在係統中引入外部約束(例如,要求特定形式為零)時,如何通過分析係統的特徵值(Eigenvalues)來判斷局部解的存在性。這種分析將微分方程的求解問題轉化為對特定外微分結構特性的代數判定。 應用實例: 本部分將通過具體的幾何問題,如等距嵌入問題(Isometry Embedding Problems)或特定類型的非綫性偏微分方程,展示外微分係統在構造解或證明解的性質方麵的威力。我們將側重於如何將幾何約束轉化為形式語言,並通過係統的代數操作來推進幾何分析。 總結與展望 本書的結構設計力求在介紹深奧概念時保持清晰的層次感。從流形的微積分,到對稱性的李代數描述,再到利用外微分係統解決復雜的微分方程幾何,讀者將獲得一套完整的現代幾何分析工具箱。它不僅是理論學習的教材,更是一份引導讀者進入微分幾何前沿研究的路綫圖。最終目標是讓讀者能夠獨立地運用這些強大的數學語言,去解析和構建復雜的幾何模型。