內容簡介
More precisely, by (i), I mean a systematic presentation of the materialgoverned by the desire for mathematical perfection and completeness ofthe results. In contrast to (i), approach (ii) starts out from the question"What are the most important applications?" and then tries to answer thisquestion as quickly as possible. Here, one walks directly on the main roadand does not wander into all the nice and interesting side roads.
The present book is based on the second approach. It is addressed toundergraduate and beginning graduate students of mathematics, physics,and engineering who want to learn how functional analysis elegantly solvesma~hematical problems that are related to our real world azld that haveplayed an important role in the history of mathematics. The reader shouldsense that the theory is being developed, not simply for its own sake, butfor the effective solution of concrete problems.
內頁插圖
目錄
Preface
Contents of AMS Volume 108
1 The Hahn-Banach Theorem Optimization Problems
1.1 The Hahn-Banach Theorem
1.2 Applications to the Separation of Convex Sets
1.3 The Dual Space C[a, b]*
1.4 Applications to the Moment Problem
1.5 Minimum Norm Problems and Duality Theory
1.6 Applications to Cebysev Approximation
1.7 Applications to the Optimal Control of Rockets
2 Variational Principles and Weak Convergence
2.1 The nth Variation
2.2 Necessary and Sufficient Conditions for Local Extrema and the Classical Calculus of Variations
2.3 The Lack of Compactness in Infinite-Dimensional Banach Spaces
2.4 Weak Convergence
2.5 The Generalized Weierstrass Existence Theorem
2.6 Applications to the Calculus of Variations
2.7 Applications to Nonlinear Eigenvalue Problems
2.8 Reflexive Banach Spaces
2.9 Applications to Convex Minimum Problems and Variational Inequalities
2.10 Applications to Obstacle Problems in Elasticity
2.11 Saddle Points
2.12 Applications to Dui~lity Theory
2.13 The von Neumann Minimax Theorem on the Existence of Saddle Points
2.14 Applications to Game Theory
2.15 The Ekeland Principle about Quasi-Minimal Points
2.16 Applications to a General Minimum Principle via the Palais-Smale Condition
2.17 Applications to the Mountain Pass Theorem
2.18 The Galerkin Menhod and Nonlinear Monotone Operators
2.19 Symmetries and Conservation Laws (The Noether Theorem
2.20 The Basic Ideas of Gauge Field Theory
2.21 Representations of Lie Algebras
2.22 Applications to Elementary Particles
3 Principles of Linear Functional Analysis
3.1 The Baire Theorem
3.2 Application to the Existence of Nondifferentiable Continuous Functions
3.3 The Uniform Boundedness Theorem
3.4 Applications to Cubature Formulas
3.5 The Open Mapping Theorem
3.6 Product Spaces
3.7 The Closed Graph Theorem
3.8 Applications to Factor Spaces
3.9 Applications to Direct Sums and Projections
3.10 Dual Operators
3.11 The Exactness of the Duality Functor
3.12 Applications to the Closed Range Theorem and to Fredholm Alternatives
4 The Implicit Function Theorem
4.1 m-Linear Bounded Operators
4.2 The Differential of Operators and the Fr~chet Derivative
4.3 Applications to Analytic Operators
4.4 Integration
4.5 Applications to the Taylor Theorem
4.6 Iterated Derivatives
4.7 The Chain Rule
4.8 The Implicit Function Theorem
4.9 Applications to Differential Equations
4.10 Diffeomorphisms and the Local Inverse Mapping Theorem
4.11 Equivalent Maps and the Linearization Principle
4.12 The Local Normal Form for Nonlinear Double Splitting Maps
4.13 The Surjective Implicit Function Theorem
4.14 Applications to the Lagrange Multiplier Rule
5 Fredholm Operators
5.1 Duality for Linear Compact Operators
5.2 The Riesz-Schauder Theory on Hilbert Spaces
5.3 Applications to Integral Equations
5.4 Linear Fredholm Operators
5.5 The Riesz-Schauder Theory on Banach Spaces
5.6 Applications to the Spectrum of Linear Compact Operators
5.7 The Parametrix
5.8 Applications to the Perturbation of Fredholm Operators
5.9 Applications to the Product Index Theorem
5.10 Fredholm Alternatives via Dual Pairs
5.11 Applications to Integral Equations and Boundary-Value Problems
5.12 Bifurcation Theory
5.13 Applications to Nonlinear Integral Equations
5.14 Applications to Nonlinear Boundary-Value Problems
5.15 Nonlinear Fredholm Operators
5.16 Interpolation Inequalities
5.17 Applications to the Navier-Stokes Equations References
List of Symbols
List of Theorems
List of Most Important Definitions
Subject Index
前言/序言
More precisely, by (i), I mean a systematic presentation of the materialgoverned by the desire for mathematical perfection and completeness ofthe results. In contrast to (i), approach (ii) starts out from the question"What are the most important applications?" and then tries to answer thisquestion as quickly as possible. Here, one walks directly on the main roadand does not wander into all the nice and interesting side roads.
The present book is based on the second approach. It is addressed toundergraduate and beginning graduate students of mathematics, physics,and engineering who want to learn how functional analysis elegantly solvesma~hematical problems that are related to our real world azld that haveplayed an important role in the history of mathematics. The reader shouldsense that the theory is being developed, not simply for its own sake, butfor the effective solution of concrete problems.
數學分析進階:經典拓撲學與測度論基礎 一部深入探討現代數學核心概念的權威著作 本書旨在為高等數學學習者、研究生以及專業研究人員提供一套嚴謹而全麵的數學分析基礎,重點聚焦於拓撲學和測度論這兩個對現代數學至關重要的分支。本書的敘述風格力求清晰、邏輯嚴密,旨在不僅傳授知識點,更培養讀者對抽象結構和嚴格證明的深刻理解。 全書內容組織圍繞兩個核心支柱展開:拓撲空間的基礎理論與勒貝格測度及積分理論的構建。我們認為,隻有堅實地掌握瞭這兩個工具,纔能有效地推進到泛函分析、概率論、微分幾何乃至更高級的領域。 --- 第一部分:拓撲學基礎——空間的幾何與結構 本部分緻力於構建拓撲學的完整框架,這是理解“接近性”、“連續性”以及“收斂性”在更廣闊空間中如何運作的基石。 第一章:集閤論迴顧與基礎概念 雖然集閤論是預備知識,但本章將從現代數學的視角快速迴顧必要的集閤論工具,特彆是關於選擇公理(Axiom of Choice)在構造某些數學對象(如Hamel基)時的必要性討論。重點將放在序關係、良序定理以及超限歸納法的初步應用上,為後續抽象空間的構建打下基礎。 第二章:拓撲空間的定義與基本性質 本章是拓撲學的核心起點。我們將從開集、閉集的定義齣發,係統闡述拓撲空間的公理化結構。隨後,深入探討以下關鍵概念: 開集與閉集的對偶關係: 閉包(Closure)、內部(Interior)、邊界(Boundary)的精確定義及其相互關係。 鄰域係統(Neighborhood Systems): 從局部視角理解拓撲結構,特彆是對於$mathbb{R}^n$中的度量空間到一般拓撲空間的過渡。 基與相對拓撲: 如何通過較少的集閤(基)生成整個拓撲結構;子空間的相對拓撲概念及其在嵌入理論中的重要性。 第三章:連續性與拓撲同胚 連續性是泛函分析的生命綫。本章將拓撲學中的連續性定義推廣到任意拓撲空間之間,並將其與集閤的開/閉映射聯係起來。 連續函數的特徵: 使用原像(Preimage)性質定義連續性,並與度量空間中的$epsilon-delta$定義進行詳細比較和統一。 拓撲同胚(Homeomorphism): 嚴格定義拓撲性質的保持,理解兩個空間在拓撲意義上是否“相同”。討論拓撲不變量(如連通性、緊緻性)的概念。 第四章:重要的拓撲性質:緊緻性與連通性 緊緻性和連通性是區分拓撲空間結構差異的兩個最重要工具。 連通性: 定義連通空間和路徑連通空間。探討連通集的代數性質(如開集的並集、閉集的交集)。 緊緻性(Compactness): 引入開覆蓋的定義,並嚴格證明Heine-Borel定理(在有限維歐氏空間中的等價性)。緊緻性在函數空間的均勻收斂理論中扮演的關鍵角色將被提前預示。 第五章:分離公理與特殊拓撲空間 本章將探討拓撲空間的“良好程度”,即它們在多大程度上類似於我們熟悉的度量空間。 分離公理(Separation Axioms): 從$T_0$到著名的Hausdorff空間($T_2$)。證明所有度量空間都是Hausdorff的,並討論非Hausdorff空間的例子及其病態性質。 正則性與完全正則性($T_3, T_4$): 這些公理是構造度量、一緻性等結構的前提。 完備性初步: 引入可數緊緻性和可微緊緻性,並討論它們與緊緻性的關係,為後續測度論中的收斂性提供鋪墊。 --- 第二部分:測度論——量化集閤的“大小” 本部分將從嚴謹的數學角度構建對“長度”、“麵積”、“體積”的抽象推廣——勒貝格測度。這是概率論和積分理論的基石。 第六章:外測度與勒貝格可測集的構造 傳統黎曼積分的局限性促使我們需要一種更強大的積分工具。本章從基礎的卡拉索多裏外測度(Carathéodory Outer Measure)齣發,逐步篩選齣滿足特定性質的子集。 長度與外測度: 定義可數集的長度(Lebesgue Measure of Countable Sets)為零。 卡拉索多裏 $sigma$-可加性條件: 嚴格定義勒貝格可測集。證明可測集的$sigma$-代數結構。 勒貝格測度的性質: 證明其平移不變性、單調性、次可加性以及最重要的可數可加性(Countable Additivity)。 第七章:可測函數與積分的構建 有瞭可測集,下一步便是定義在這些集閤上的函數及其積分。 可測函數: 定義可測函數的精確標準(原像為可測集),並證明簡單函數和連續函數是可測的。 簡單函數積分: 建立最基礎的積分概念。 勒貝格積分的定義: 通過逼近可測函數序列來定義勒貝格積分,並證明其比黎曼積分更為強大。 第八章:積分的收斂定理 勒貝格積分的優越性很大程度上體現在其強大的收斂定理上,這些定理使得在積分號下交換極限成為可能。 單調收斂定理(Monotone Convergence Theorem, MCT): 給齣積分何時可以與非降函數序列的極限交換順序的充分條件。 法圖引理(Fatou's Lemma): 作為MCT與DCT之間的橋梁,其證明技巧本身具有重要啓發意義。 支配收斂定理(Dominated Convergence Theorem, DCT): 最常用且最強大的定理,要求函數序列被一個可積函數所“支配”。詳細分析其在傅裏葉分析和微分方程中的應用潛力。 第九章:Lp空間與測度論的拓撲結構 本章將測度論與第一部分建立的拓撲學框架結閤起來,引入函數空間的核心概念。 $L^p$ 空間的定義: 定義$L^p(mu)$空間,並討論其結構。 Minkowski不等式與$L^p$空間的度量結構: 證明$L^p$空間在$p ge 1$時構成一個度量空間(當$p=2$時,構成希爾伯特空間的基礎)。 Riesz-Fischer定理(初步): 闡述$L^p$空間(特彆是$L^2$)的完備性,即它們是Banach空間。這為後續泛函分析的展開奠定瞭堅實的度量基礎。 --- 總結與展望 本書的結構精心設計,確保瞭從基礎的集閤論到抽象的拓撲結構,再到嚴格的測度論構建,每一步都建立在前一步的基礎上。通過對拓撲性質(如緊緻性、連通性)和積分性質(如收斂性)的深入探討,讀者將為進入更專業的泛函分析、調和分析或隨機過程的研究做好充分準備。本書強調理論的內在聯係與嚴謹的證明邏輯,是追求數學深度理解的讀者的理想教材。