內容簡介
     This book is intended as an introduction to fixed point theory and itsapplications. The topics treated range from fairly standard results (such asthe Principle of Contraction Mapping, Brouwers and Schauders fixedpoint theorems) to the frontier of what is known, but we have not tried toachieve maximal generality in all possible directions. We hope that thereferences quoted may be useful for this purpose.
  The point of view adopted in this book is that of functional analysis; forthe readers more interested in the algebraic topological point of view wehave added some references at the end of the book. A knowledge offunctional analysis is not a prerequisite, although a knowledge of anintroductory course in functional analysis would be profitable. However,the book contains two introductory chapters, one on general topology andanother on Banach and Hilbert spaces.     
內頁插圖
          目錄
   Editors Preface
Foreword
CHAPTER 1. Topological Spaces and Topological Linear Spaces
1.1. Metric Spaces
1.2. Compactness in Metric Spaces. Measures of Noncompactness
1.3. Baire Category Theorem
1.4. Topological Spaces
1.5. Linear Topological Spaces. Locally Convex Spaces
CHAPTER 2. Hilbert spaces and Banach spaces
2.1. Normed Spaces. Banach Spaces
2.2. Hilbert Spaces
2.3. Convergence in X, X* and L(X)
2.4. The Adjoint of an Operator
2.5. Classes of Banach Spaces
2.6. Measures of Noncompactness in Banach Spaces
2.7. Classes of Special Operators on Banach Spaces
CHAPTER 3. The Contraction Principle
3.0. Introduction
3.1. The Principle of Contraction Mapping in Complete Metric Spaces
3.2. Linear Operators and Contraction Mappings
3.3. Some Generalizations of the Contraction Mappings
3.4. Hilberts Projective Metric and Mappings of Contractive Type
3.5. Approximate Iteration
3.6. A Converse of the Contraction Principle
3.7. Some Applications of the Contraction Principle
CHAPTER 4. Brouwers Fixed Point Theorem
4.0. Introduction
4.1. The Fixed Point Property
4.2. Brouwers Fixed Point theorem. Equivalent Formulations
4.3. Robbins Complements of Brouwers Theorem
4.4. The Borsuk-Ulam Theorem
4.5. An Elementary Proof of Brouwers Theorem
4.6. Some Examples
4.7. Some Applications of Brouwers Fixed Point Theorem
4.8. The Computation of Fixed Points. Scarfs Theorem
CHAPTER 5. Schauders Fixed Point Theorem and Some Generalizations
5.0. Introduction
5.1. The Schauder Fixed Point Theorem
5.2. Darbos Generalization  of Schauders  Fixed Point Theorem
5.3. Krasnoselskiis, Rothes and Altmans Theorems
5.4. Browders and Fans Generalizations of Schauders and Tychonoffs Fixed Point Theorem
5.5. Some Applications
CHAPTER 6.  Fixed Point Theorems jbr Nonexpansive Mappings and Related Classes of Mappings
6.0. Introduction
6.1. Nonexpansive Mappings
6.2. The Extension of Nonexpansive Mappings
6.3. Some General Properties of Nonexpansive Mappings
6.4. Nonexpansive Mappings on Some Classes of Banach Spaces
6.5. Convergence of Iterations of Nonexpansive Mappings
6.6. Classes of Mappings Related to Nonexpansive Mappings
6.7. Computation of Fixed Points for Classes of Nonexpansive Mappings
6.8. A Simple Example of a Nonexpansive Mapping on a Rotund Space Without Fixed Points
CHAPTER 7. Sequences of Mappings and Fixed Points
7.0. Introduction
7.1. Convergence of Fixed Points for Contractions or Related Mappings
7.2. Sequences of Mappings and Measures of Noncompactness
CHAPTER 8. Duality Mappings amt Monotome Operators
8.0. Introduction
8.1. Duality Mappings
8.2. Monotone Mappings and Classes of Nonexpansive Mappings
8.3. Some Surjectivity Theorems on Real Banach Spaces
8.4. Some Surjectivity Theorems in Complex Banach Spaces
8.5. Some Surjectivity Theorems in Locally Convex Spaces
8.6. Duality Mappings and Monotonicity for Set-Valued Mappings
8.7. Some Applications
CHAPTER 9. Families of Mappings and Fixed Points
9.0. Introduction
9.1. Markovs and Kakutanis Results
9.2. The RylI-Nardzewski Fixed Point Theorem
9.3. Fixed Points for Families of Nonexpansive Mappings
9.4. lnvariant Means on Semigroups and Fixed Point for Families of Mappings
CHAPTER 10. Fixed Points and Set-Valued Mappings
10.0 Introduction
10.1 The Pompeiu-Hausdorff Metric
10.2. Continuity for Set-Valued Mappings
10.3. Fixed Point Theorems for Some Classes of Set-valued Mappings
10.4. Set-Valued Contraction Mappings
10.5. Sequences of Set-Valued Mappings and Fixed Points
CHAPTER 11. Fixed Point Theorems for Mappings on PM-Spaces
11.0. Introduction
11.1. PM-Spaces
11.2. Contraction Mappings in PM-Spaces
11.3. Probabilistic Measures of Noncompactness
11.4. Sequences of Mappings and Fixed Points
CHAPTER 12. The Topological Degree
12.0.Introduction
12.1. The Topological Degree in Finite-Dimensional Spaces
12.2. The Leray-Schauder Topological Degree
12.3. Lerays Example
12.4. The Topological Degree for k-Set Contractions
12.5. The Uniqueness Problem for the Topological Degree
I2.6. The Computation of the Topological Degree
12.7. Some Applications of the Topological Degree
BIBLIOGRAPHY
INDEX      
前言/序言
     This book is intended as an introduction to fixed point theory and itsapplications. The topics treated range from fairly standard results (such asthe Principle of Contraction Mapping, Brouwers and Schauders fixedpoint theorems) to the frontier of what is known, but we have not tried toachieve maximal generality in all possible directions. We hope that thereferences quoted may be useful for this purpose.
  The point of view adopted in this book is that of functional analysis; forthe readers more interested in the algebraic topological point of view wehave added some references at the end of the book. A knowledge offunctional analysis is not a prerequisite, although a knowledge of anintroductory course in functional analysis would be profitable. However,the book contains two introductory chapters, one on general topology andanother on Banach and Hilbert spaces. As a special feature of these chapterswe note the study of measures of noncompactness; first in the case of metricspaces, and second in the case of Banach spaces.
  Chapter 3 contains a detailed account of the Contraction Principle,perhaps the best known fixed point theorem. Many generalizations of theContraction Principle are also included. We note here the connectionbetween ideas from projective geometry and contractive mappings. Afterpresenting some ways to compute the fixed points for contractivemappings, we discuss several applications in various areas. Chapter 4 presents Brouwers fixed point theorem, perhaps the mostimportant fixed point theorem. After some historical notes concerningopinions about Brouwers proof- which have been influential for the futureof the fixed point theory (Alexander and Birkhoff and Kellogg)-wepresent many proofs of this theorem of Brouwer, of interest to differentcategories of readers. Thus we present an elementary one, which requiresonly elementary properties of polynomials and continuous functions;another uses differential forms; still another uses differential topology; andone relies on combinatorial topology. These different proofs may be used indifferent ways to compute the fixed points for mappings. In this connection,some algorithms for the computation of fixed points are given.    
				
 
				
				
					《不動點理論導論(英文版)》圖書簡介  書名: 《不動點理論導論(英文版)》 (Fixed Point Theory: An Introduction)  導論:不動點理論的深遠影響與核心概念  不動點理論,作為數學分析和拓撲學的一個核心分支,其重要性已遠遠超越瞭理論研究的範疇,深入到眾多應用科學的基石之中。從經濟學中的均衡分析到物理學中的穩定態研究,再到計算機科學中的算法收斂性證明,不動點理論提供瞭一種強有力的工具,用以論證特定方程或映射在給定空間中必然存在“不動點”——即輸入與輸齣完全相同的點。  本書《不動點理論導論(英文版)》正是為有誌於深入探索這一迷人領域的讀者精心編纂的入門性教材。它旨在係統而清晰地介紹不動點理論的基本概念、經典定理及其在數學及相關學科中的應用,為初學者構建堅實的理論基礎,同時為資深研究者提供一個結構化的迴顧平颱。  本書的敘述風格力求嚴謹而不失啓發性,內容組織遵循從基礎到深入、從經典到現代的邏輯脈絡。我們專注於清晰地闡述數學直覺與嚴格證明之間的橋梁,確保讀者不僅理解“定理為什麼成立”,更能掌握“如何運用這些定理”。  第一部分:基礎奠定——度量空間與拓撲結構  不動點理論的根基深深植根於拓撲學和泛函分析之中。因此,本書的第一部分將詳盡迴顧和鞏固讀者對這些基礎概念的理解。  1.1 度量空間的基礎 我們將從度量空間的定義入手,這是不動點理論中最常用且最直觀的背景空間。內容涵蓋開集、閉集、完備性(至關重要的一環,特彆是巴拿赫空間)、緊緻性以及連續性的度量空間定義。我們強調完備性的重要性,因為它是許多核心不動點定理(如巴拿赫壓縮映射定理)得以成立的必要前提。  1.2 拓撲空間簡介 為瞭將理論推廣到更抽象的背景,我們簡要介紹瞭拓撲空間的概念,包括鄰域、開集、閉集、Hausdorff空間等基本拓撲性質。這部分內容旨在為後續更抽象的不動點存在性證明做鋪墊。  1.3 連續映射與收斂性 連續映射的定義及其在度量空間上的性質是研究迭代過程和極限行為的關鍵。我們將討論一緻收斂性與點收斂性,並引入函數空間的概念,為處理函數空間上的不動點問題打下基礎。  第二部分:經典基石——三大核心不動點定理  本書的核心內容集中在不動點理論中三座最著名、應用最廣泛的裏程碑式定理上。我們不僅詳細闡述這些定理的陳述,更著重於剖析其證明的關鍵步驟和內在邏輯。  2.1 巴拿赫壓縮映射定理(Banach Fixed Point Theorem) 作為不動點理論的“入門鑰匙”,壓縮映射定理在構造性證明中占據核心地位。我們將詳細討論壓縮映射的定義、完備度量空間上的唯一不動點存在性證明,並深入分析其實際應用,例如證明常微分方程(ODE)的局部解的存在性(通過皮卡迭代法)。我們還將討論該定理的誤差估計及其在數值分析中的重要性。  2.2 布勞威爾不動點定理(Brouwer Fixed Point Theorem) 布勞威爾定理將不動點理論提升到瞭更抽象的拓撲層麵。我們介紹二維和三維情況下的直觀幾何意義,隨後轉嚮 $n$ 維標準單純形 $Delta^n$ 上的證明。本書將采用拓撲學中更易於理解的證明思路(例如基於奇偶性的論證或與度函數相關的概念),以期幫助讀者掌握這一非構造性定理的精髓。該定理在經濟學(如瓦爾拉斯均衡)中的應用將被著重討論。  2.3 龐加萊鏇轉嚮量定理(Poincaré Fixed Point Theorem)及其推廣 雖然不如前兩者那樣常用,但龐加萊定理在特定幾何背景下具有重要意義。本章節將介紹在緊緻凸集上的映射不動點問題,並自然過渡到更具包容性的捨弗定理。  第三部分:泛化與擴展——更廣闊的函數空間  在奠定瞭度量空間上的基礎後,本書將視野擴展到更抽象、更強大的函數空間,特彆是賦範綫性空間和更一般的一緻凸巴拿赫空間。  3.1 捨弗不動點定理(Schauder Fixed Point Theorem) 捨弗定理是布勞威爾定理在無限維空間中的推廣,它在處理偏微分方程(PDE)的解的存在性問題中起著決定性作用。我們將討論在凸緊集上的連續映射不動點存在性,並分析該定理在形式化證明中所涉及的拓撲工具,如緊集、分離性等。  3.2 不動點理論在凸優化中的應用 我們將探討不動點理論與變分不等式、均衡問題之間的密切關係。特彆是對Kakutani不動點定理的介紹,它在非閤作博弈論和經濟均衡模型中提供瞭強有力的理論支持。  3.3 更一般的拓撲不動點理論 為瞭完成理論的閉環,本書將簡要介紹不動點理論在更一般拓撲結構下的結果,包括一些基於吸引性(Contractive-like mappings)的概念,以及如何利用不動點理論來分析迭代過程的穩定性。  第四部分:應用聚焦——不動點理論的實踐價值  理論的價值在於其應用性。本書的最後一部分將聚焦於不動點理論如何在具體的數學分支中發揮作用。  4.1 常微分方程(ODEs) 詳細展示皮卡-林德勒夫(Picard-Lindelöf)定理的證明如何直接依賴於巴拿赫壓縮映射定理,並討論柯西問題解的存在性與唯一性。  4.2 積分方程與泛函分析 討論如何將某些綫性與非綫性積分方程轉化為函數空間上的不動點問題,並利用捨弗定理證明這些方程的解的存在性。  4.3 經濟學與博弈論 深入探討布勞威爾定理和Kakutani定理在證明市場均衡、納什均衡存在性中的關鍵作用,展示不動點理論如何成為現代經濟學分析的數學骨架。  結論與展望  《不動點理論導論(英文版)》旨在成為一本結構完整、內容豐富的學習指南。通過對經典定理的深入剖析和對現代應用的恰當介紹,本書力求使讀者不僅掌握不動點理論的工具箱,更能體會到這一數學領域跨越多個學科的普適之美和強大力量。本書的編寫遵循數學教材的最高標準,注重概念的清晰界定和證明的邏輯嚴密性,確保讀者在學習過程中獲得紮實的理論功底和開闊的應用視野。