內容簡介
Complex geometry is a highly attractive branch of modern mathematics that has witnessed many years of active and successful research and that has re- cently obtained new impetus from physicists interest in questions related to mirror symmetry. Due to its interactions with various other fields (differential, algebraic, and arithmetic geometry, but also string theory and conformal field theory), it has become an area with many facets. Also, there are a number of challenging open problems which contribute to the subjects attraction. The most famous among them is the Hodge conjecture, one of the seven one-million dollar millennium problems of the Clay Mathematics Institute. So, it seems likely t at this area will fascinate new generations for many years to come.
內頁插圖
目錄
1 Local Theory
1.1 Holomorphic Functions of Several Variables
1.2 Complex and Hermitian Structures
1.3 Differential Forms
2 Complex Manifolds
2.1 Complex Manifolds: Definition and Examples
2.2 Holomorphic Vector Bundles
2.3 Divisors and Line Bundles
2.4 The Projective Space
2.5 Blow-ups
2.6 Differential Calculus on Complex Manifolds
3 Kahler Manifolds
3.1 Kahler Identities
3.2 Hodge Theory on Kahler Manifolds
3.3 Lefschetz Theorems
Appendix
3.A Formality of Compact Kahler Manifolds
3.B SUSY for Kahler Manifolds
3.C Hodge Structures
4 Vector Bundles
4.1 Hermitian Vector Bundles and Serre Duality
4.2 Connections
4.3 Curvature
4.4 Chern Classes
Appendix
4.A Levi-Civita Connection and Holonomy on Complex Manifolds
4.B Hermite-Einstein and Kahler-Einstein Metrics
5 Applications of Cohomology
5.1 Hirzebruch-Riemann-Roch Theorem
5.2 Kodaira Vanishing Theorem and Applications
5.3 Kodaira Embedding Theorem
Deformations of Complex Structures
6.1 The Maurer-Cartan Equation
6.2 General Results
Appendix
6.A dGBV-Algebras
A Hodge Theory on Differentiable Manifolds
B Sheaf Cohomology
References
Index
前言/序言
Complex geometry is a highly attractive branch of modern mathematics thathas witnessed many years of active and successful research and that has recently obtained new impetus from physicists interest in questions related tomirror symmetry. Due to its interactions with various other fields (differential,algebraic, and arithmetic geometry, but also string theory and conformal fieldtheory), it has become an area with many facets. Also, there are a number ofchallenging open problems which contribute to the subjects attraction. Themost famous among them is the Hodge conjecture, one of the seven one-milliondollar millennium problems of the Clay Mathematics Institute. So, it seemslikely that this area will fascinate new generations for many years to come.
Complex geometry, as presented in this book, studies the geometry of(mostly compact) complex manifolds. A complex manifold is a differentiablemanifold endowed with the additional datum of a complex structure which ismuch more rigid than the geometrical structures in differential geometry. Dueto this rigidity, one is often able to describe the geometry of complex manifoldsin very explicit terms. E.g. the important class of projective manifolds can, inprinciple, be described as zero sets of polynomials.
Yet, a complete classification of all compact complex manifolds is toomuch to be hoped for. Complex curves can be classified in some sense (in-volving moduli spaces etc.), but already the classification of complex surfacesis tremendously complicated and partly incomplete.
In this book we will concentrate on more restrictive types of complexmanifolds for which a rather complete theory is in store and which are alsorelevant in the applications. A prominent example are Calabi-Yau manifolds,which play a central role in questions related to mirror symmetry. Often,interesting complex manifolds are distinguished by the presence of specialRiemannian metrics. This will be one of the central themes throughout thistext. The idea is to study cases where the Riemannian and complex geometryon a differentiable manifold are not totally unrelated.
幾何學的深邃之域:從歐幾裏得到黎曼的拓撲與結構探索 內容提要: 本書旨在帶領讀者進行一場跨越時空的幾何學之旅,從古希臘的歐氏幾何基礎齣發,逐步深入到近代數學對空間本質的全新理解。我們將探討非歐幾裏得幾何的誕生及其對經典認知的顛覆,聚焦於拓撲學的核心概念,並觸及微分幾何在描述復雜麯麵和流形上的強大應用。全書強調幾何直覺與嚴謹邏輯的結閤,旨在構建一個清晰、全麵的現代幾何學圖景,為理解物理學、現代拓撲乃至更抽象的數學結構打下堅實的基礎。本書將避開復分析的特定領域,專注於實數域上的空間形態、度量和連續變換。 --- 第一章:歐氏空間的堅實基石與經典悖論 本章伊始,我們將迴顧歐幾裏得幾何的五大公設,特彆是其第五公設(平行公設)在兩韆多年間所引發的深刻危機。我們將詳細分析在保持其他四條公設不變的情況下,對第五公設進行否定或修改所必然導緻的幾何係統——非歐幾何的預兆。 公理係統的完備性與獨立性探究: 深入剖析希爾伯特公理化係統如何為歐氏幾何提供一個更為嚴謹的邏輯框架。重點討論點、綫、平麵之間的關係,以及順序、分割和全等這些基本概念的公理化錶達。 度量與剛體運動: 歐氏幾何的標誌在於其固有的距離和角度概念,這些概念是通過剛體運動(平移和鏇轉)來保持不變的。本節將嚴格定義歐氏距離公式,並探討通過等距變換(Isometries)來刻畫空間結構的方法。 幾何直覺的局限性: 通過對高維歐氏空間的有限度可視化嘗試,揭示人類直覺在處理超過三維空間時的局限性,從而引齣研究抽象空間的必要性。 第二章:非歐幾何的革命:空間的內在麯率 第五公設的叛逆催生瞭兩個主要的非歐幾何體係:羅巴切夫斯基幾何(雙麯幾何)和黎曼幾何(橢圓幾何的早期形態)。本章將詳細構建這些體係,理解它們與歐氏幾何在基本性質上的根本區彆。 雙麯幾何(羅巴切夫斯基/波雅伊): 重點討論在平麵上,過一點有無數條不與給定直綫相交的直綫(平行綫)。我們將使用龐加萊圓盤模型和雙麯麵模型來可視化這種負麯率空間。分析雙麯三角形的內角和恒小於 $pi$ 的驚人結論,及其對三角函數關係(如雙麯正弦和餘弦)的重構。 橢圓幾何(球麵幾何): 作為正麯率空間的代錶,球麵幾何中不存在平行綫,任意兩條“直綫”(大圓)必然相交。分析球麵三角形的內角和恒大於 $pi$ 的性質,以及地理學和天文學中球麵幾何的應用。 高斯的可展性理論與麯率的定義: 引入高斯“奇想”——著名的“絕妙定理”(Theorema Egregium)。該定理指齣,高斯麯率僅由第一基本形式決定,而與空間嵌入的外部環境無關。這標誌著麯率從依賴於嵌入空間的量,轉變為空間自身的內在屬性。 第三章:拓撲學的誕生:不變量與形變 本章將從關注長度、角度的度量幾何,轉嚮關注“連續性”和“形變”的拓撲學。拓撲學是對那些在連續形變(拉伸、彎麯,但不撕裂或粘閤)下保持不變的性質的研究。 拓撲等價與同胚: 嚴格定義同胚(Homeomorphism)的概念,它代錶瞭拓撲學中的“等價”。討論杯子和甜甜圈(環麵)為何是拓撲等價的,而球體和圓環麵則不是。 拓撲不變量: 深入探討能夠區分不同拓撲空間的量。 連通性: 討論路徑連通性與道路連通性的區彆。 洞的數量(虧格/Genus): 引入虧格的概念,作為區分二維流形拓撲類型的主要拓撲不變量。 歐拉示性數(Euler Characteristic): 介紹歐拉示性數 $chi = V - E + F$ 在多麵體上的計算,並將其推廣到任意緊緻可定嚮的二維流形,展示它在拓撲分類中的核心作用。 緊緻性與分離公理: 介紹拓撲空間理論中的兩個關鍵性質:緊緻性(Compactness)對連續函數最大值存在性的保證,以及分離公理(如Hausdorff性質)對局部結構描述的必要性。 第四章:流形的概念與微分幾何的初步接觸 為瞭在光滑的麯麵上進行微積分運算,我們需要一個局部看起來像歐氏空間的數學對象——流形。本章將建立起從局部到整體的橋梁。 $n$ 維流形的定義: 形式化定義一個拓撲流形:一個Hausdorff空間,局部上同胚於 $mathbb{R}^n$ 的空間。討論切綫空間的概念,它是流形上每一點的“局部歐氏近似”。 光滑結構與坐標圖冊: 解釋為什麼僅僅有拓撲結構是不夠的,我們需要“光滑結構”(即坐標變換是光滑的)纔能在流形上進行微分運算。引入圖冊(Atlas)和轉移映射(Transition Maps)的概念。 度量張量與黎曼流形: 在光滑流形上引入度量張量的概念,它是一個定義在每一點切空間上的正定二次型。黎曼流形即是配備瞭度量張量的光滑流形。 測地綫(Geodesics): 討論測地綫是流形上兩點之間“最短路徑”的推廣。在局部,測地綫可以看作是無加速度的運動軌跡,其定義依賴於度量張量所導齣的連接係數(Christoffel符號)。 第五章:從麯率到幾何的統一:黎曼幾何的廣闊視野 本章將超越二維麯麵,進入高維黎曼流形的領域,探討麯率如何影響空間中的幾何性質。 黎曼麯率張量: 介紹黎曼麯率張量的精確定義,它量化瞭平行移動(在流形上“攜帶”嚮量)時,嚮量鏇轉偏離初始方嚮的程度。麯率張量是描述流形彎麯程度的最精細的內在工具。 截麵麯率與豐富性: 討論截麵麯率(Sectional Curvature),它是在流形上任意二維平麵上測得的高斯麯率的推廣。通過截麵麯率的正負,我們可以直觀地理解空間的局部幾何行為。 測地綫的發散與時空結構: 探討在不同麯率空間中,鄰近測地綫的行為差異(例如,在正麯率空間中會嚮內收縮,在負麯率空間中則會迅速發散)。這為理解廣義相對論中時空彎麯的幾何後果提供瞭必要的數學框架。 --- 本書的特色與讀者對象: 本書結構清晰,邏輯遞進自然,力求在保持數學嚴謹性的同時,激發讀者的幾何洞察力。它不依賴於復雜的代數工具,而是通過構造性論證和模型可視化來深化理解。本書特彆適閤: 1. 高等數學和物理學專業學生,作為他們進入微分幾何、廣義相對論或高維拓撲學課程的預備讀物。 2. 對空間結構和連續性本質有深刻好奇心的數學愛好者,他們希望超越傳統歐氏幾何的界限,探索現代幾何學的核心概念。 3. 需要迴顧或係統學習非歐幾何和黎曼幾何基礎的科研人員。 通過對歐氏空間、非歐空間、拓撲不變量以及黎曼流形的係統性考察,讀者將對“空間”這一核心概念獲得一個更為豐富和精確的理解。