内容简介
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.
内页插图
目录
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.
数学分析进阶:经典拓扑学与测度论基础 一部深入探讨现代数学核心概念的权威著作 本书旨在为高等数学学习者、研究生以及专业研究人员提供一套严谨而全面的数学分析基础,重点聚焦于拓扑学和测度论这两个对现代数学至关重要的分支。本书的叙述风格力求清晰、逻辑严密,旨在不仅传授知识点,更培养读者对抽象结构和严格证明的深刻理解。 全书内容组织围绕两个核心支柱展开:拓扑空间的基础理论与勒贝格测度及积分理论的构建。我们认为,只有坚实地掌握了这两个工具,才能有效地推进到泛函分析、概率论、微分几何乃至更高级的领域。 --- 第一部分:拓扑学基础——空间的几何与结构 本部分致力于构建拓扑学的完整框架,这是理解“接近性”、“连续性”以及“收敛性”在更广阔空间中如何运作的基石。 第一章:集合论回顾与基础概念 虽然集合论是预备知识,但本章将从现代数学的视角快速回顾必要的集合论工具,特别是关于选择公理(Axiom of Choice)在构造某些数学对象(如Hamel基)时的必要性讨论。重点将放在序关系、良序定理以及超限归纳法的初步应用上,为后续抽象空间的构建打下基础。 第二章:拓扑空间的定义与基本性质 本章是拓扑学的核心起点。我们将从开集、闭集的定义出发,系统阐述拓扑空间的公理化结构。随后,深入探讨以下关键概念: 开集与闭集的对偶关系: 闭包(Closure)、内部(Interior)、边界(Boundary)的精确定义及其相互关系。 邻域系统(Neighborhood Systems): 从局部视角理解拓扑结构,特别是对于$mathbb{R}^n$中的度量空间到一般拓扑空间的过渡。 基与相对拓扑: 如何通过较少的集合(基)生成整个拓扑结构;子空间的相对拓扑概念及其在嵌入理论中的重要性。 第三章:连续性与拓扑同胚 连续性是泛函分析的生命线。本章将拓扑学中的连续性定义推广到任意拓扑空间之间,并将其与集合的开/闭映射联系起来。 连续函数的特征: 使用原像(Preimage)性质定义连续性,并与度量空间中的$epsilon-delta$定义进行详细比较和统一。 拓扑同胚(Homeomorphism): 严格定义拓扑性质的保持,理解两个空间在拓扑意义上是否“相同”。讨论拓扑不变量(如连通性、紧致性)的概念。 第四章:重要的拓扑性质:紧致性与连通性 紧致性和连通性是区分拓扑空间结构差异的两个最重要工具。 连通性: 定义连通空间和路径连通空间。探讨连通集的代数性质(如开集的并集、闭集的交集)。 紧致性(Compactness): 引入开覆盖的定义,并严格证明Heine-Borel定理(在有限维欧氏空间中的等价性)。紧致性在函数空间的均匀收敛理论中扮演的关键角色将被提前预示。 第五章:分离公理与特殊拓扑空间 本章将探讨拓扑空间的“良好程度”,即它们在多大程度上类似于我们熟悉的度量空间。 分离公理(Separation Axioms): 从$T_0$到著名的Hausdorff空间($T_2$)。证明所有度量空间都是Hausdorff的,并讨论非Hausdorff空间的例子及其病态性质。 正则性与完全正则性($T_3, T_4$): 这些公理是构造度量、一致性等结构的前提。 完备性初步: 引入可数紧致性和可微紧致性,并讨论它们与紧致性的关系,为后续测度论中的收敛性提供铺垫。 --- 第二部分:测度论——量化集合的“大小” 本部分将从严谨的数学角度构建对“长度”、“面积”、“体积”的抽象推广——勒贝格测度。这是概率论和积分理论的基石。 第六章:外测度与勒贝格可测集的构造 传统黎曼积分的局限性促使我们需要一种更强大的积分工具。本章从基础的卡拉索多里外测度(Carathéodory Outer Measure)出发,逐步筛选出满足特定性质的子集。 长度与外测度: 定义可数集的长度(Lebesgue Measure of Countable Sets)为零。 卡拉索多里 $sigma$-可加性条件: 严格定义勒贝格可测集。证明可测集的$sigma$-代数结构。 勒贝格测度的性质: 证明其平移不变性、单调性、次可加性以及最重要的可数可加性(Countable Additivity)。 第七章:可测函数与积分的构建 有了可测集,下一步便是定义在这些集合上的函数及其积分。 可测函数: 定义可测函数的精确标准(原像为可测集),并证明简单函数和连续函数是可测的。 简单函数积分: 建立最基础的积分概念。 勒贝格积分的定义: 通过逼近可测函数序列来定义勒贝格积分,并证明其比黎曼积分更为强大。 第八章:积分的收敛定理 勒贝格积分的优越性很大程度上体现在其强大的收敛定理上,这些定理使得在积分号下交换极限成为可能。 单调收敛定理(Monotone Convergence Theorem, MCT): 给出积分何时可以与非降函数序列的极限交换顺序的充分条件。 法图引理(Fatou's Lemma): 作为MCT与DCT之间的桥梁,其证明技巧本身具有重要启发意义。 支配收敛定理(Dominated Convergence Theorem, DCT): 最常用且最强大的定理,要求函数序列被一个可积函数所“支配”。详细分析其在傅里叶分析和微分方程中的应用潜力。 第九章:Lp空间与测度论的拓扑结构 本章将测度论与第一部分建立的拓扑学框架结合起来,引入函数空间的核心概念。 $L^p$ 空间的定义: 定义$L^p(mu)$空间,并讨论其结构。 Minkowski不等式与$L^p$空间的度量结构: 证明$L^p$空间在$p ge 1$时构成一个度量空间(当$p=2$时,构成希尔伯特空间的基础)。 Riesz-Fischer定理(初步): 阐述$L^p$空间(特别是$L^2$)的完备性,即它们是Banach空间。这为后续泛函分析的展开奠定了坚实的度量基础。 --- 总结与展望 本书的结构精心设计,确保了从基础的集合论到抽象的拓扑结构,再到严格的测度论构建,每一步都建立在前一步的基础上。通过对拓扑性质(如紧致性、连通性)和积分性质(如收敛性)的深入探讨,读者将为进入更专业的泛函分析、调和分析或随机过程的研究做好充分准备。本书强调理论的内在联系与严谨的证明逻辑,是追求数学深度理解的读者的理想教材。