全書共分成8章,主要包括:復數(shù)、復函數(shù)、作為映射的解析函數(shù)、復積分、級數(shù)與乘積展開、共形映射、狄利克雷問題、橢圓函數(shù)以及全局解析函數(shù)。此外,大部分章節(jié)后都有練習,便于學生掌握書中內(nèi)容,其中加上“*”號的練習供學有余力的學生選做。本書假定讀者具備大學二年級的數(shù)學基礎,可作為高等院校高年級本科生以及研究生的教材和參考書。
適讀人群 :高等院校高年級本科生以及研究生
復分析研究復自變量復值函數(shù),是數(shù)學的重要分支之一,同時在數(shù)學的其他分支(如微分方程、積分方程、概率論、數(shù)論等)以及自然科學的其他領域(如空氣動力學、流體力學、電學、熱學、理論物理等)都有著重要的應用。
雖然本書的誕生是20世紀50年代的事情,但是,深貫其中的嚴謹?shù)膶W術(shù)風范以及針對不同時代所做出的切實改進使得它歷久彌新,成為復分析領域歷經(jīng)考驗的一本經(jīng)典教材。本書作者在數(shù)學分析領域聲名卓著,多次榮獲國際大獎,這也是本書始終保持旺盛生命力的原因之一。
拉爾斯·V. 阿爾福斯(Lars V. Ahlfors) 生前是哈佛大學數(shù)學教授。他于1924年進入赫爾辛基大學學習,并在1930年于芬蘭著名的土爾庫大學獲得博士學位。期間他還師從著名數(shù)學家Nevanlinna共同進行研究工作。1936年榮獲菲爾茨獎。第二次世界大戰(zhàn)結(jié)束后,他輾轉(zhuǎn)到哈佛大學從事教學工作。1953年當選為美國國家科學院院士。他又于1968年和1981年分別榮獲Vihuri獎和沃爾夫獎。他的著述很多,除本書外,還著有Riemann Surfaces和Conformal lnvariants等。
Preface
CHAPTER 1 COMPLEX NUMBERS1
1 The Algebra of Complex Numbers1
1.1 Arithmetic Operations1
1.2 Square Roots3
1.3 Justification4
1.4 Conjugation, Absolute Value6
1.5 Inequalities9
2 The Geometric Representation of Complex Numbers12
2.1 Geometric Addition and Multiplication12
2.2 The Binomial Equation15
2.3 Analytic Geometry17
2.4 The Spherical Representation18
CHAPTER 2 COMPLEX FUNCTIONS21
1 Introduction to the Concept of Aaalytic Function21
1.1 Limits and Continuity22
1.2 Aaalytic Functions24
1.3 Polynomials28
1.4 Rational Functions30
2 Elementary Theory of Power Serices 33
2.1 Sequences33
2.2 Serues35
2.3 Uniform Convergence35
2.4 Power Series38
2.5 Abel's Limit Theorem41
3 The Exponential and Trigonometric Functions42
3.1 The Exponential42
3.2 The Trigonometric Functions43
3.3 The Periodicity44
3.4 The Logarithm46
CHAPTER 3 ANALYTIC FUNCTIONS AS MAPPINGS49
1 Elementary Point Set Topology50
1.1 Sets and Elements50
1.2 Metric Spaces51
1.3 Connectedness54
1.4 Connectedness59
1.5 Continuous Functions63
1.6 Topoliogical Spaces 66
2 Conformality
2.1 Arcs and Closed Curves67
2.2 Analytic Function in Regions69
2.3 Conformal Mapping73
2.4 Length and Area75
3 Linear Transformations76
3.1 The Linear Group76
3.2 The Cross Ratio78
3.3 Symmetry80
3.4 Oriented Circles83
3.5 Families of Circles84
4 Elementary Conformal Mappings89
4.1 The Use of Level Curves89
4.2 A Survey of Elementary Mappings93
4.3 Elementary Riemann Surfaces 97
CHAPTER 4 COMPLEX INTEGRATION101
1 Fundamental Theorems101
1.1 Line Integrals101
1.2 Rectifiable Arcs104
1.3 Line Integrals as Functions of Ares105
1.4 Cauchy's Theorem for a Recatangle109
1.5 Cauchy's Theorem in a Disk112
2 Cauchy's Integral Formula114
2.1 The Index of a Point with Respect to a Closed Curve114
2.2 The Integral Formula118
2.3 Higher Dervatives120
3 Local Properties of Aaalytic Functions124
3.1 Removable Singularites. Taylor's Theorem124
3.2 Zeros and Poles126
3.3 The Local Mapping130
3.4 The Mazimum Principle133
4 The General Form of Cauchy's Theorem137
4.1 Chains and Cycles 137
4.2 Siple Connectivity138
4.3 Homology141
4.4 The General Statement of Cauchy's Theorem141
4.5 Proof of Cauchy's Theorem142
4.6 Locally Exact Differentials144
4.7 Multiply Connected Regions146
5 The Calculus of Residues148
5.1 The Residue Theorem148
5.2 The Argument Principle152
5.3 Evaluation of Definite Integrals154
6 Harmonic Functions162
6.1 Definition and Basic Properties162
6.2 The Mean-value Property165
6.3 Poisson's Formula168
6.4 Schwarz's Theorem 168
6.5 The Reflection Principle172
CHAPTER 5 SERIES AND PRODUCT DEVELOPMENTS175
1 Power Serices Expansions175
1.1 Weierstrass's Theorem175
1.2 The Taylor Series179
1.3 The Laurent Series184
2 Partial Fractions and Factorzation187
2.1 Partial Fractions187
2.2 Infinite Products191
2.3 Canonical Products 193
2.4 The Gamma Function198
2.5 Stirling's Formula201
3 Entire Functions206
3.1 Jensen's Formula207
3.2 Hadamard's Theorem208
4 The Riemann Zeta Function212
4.1 The Product Development213
4.2 Extension of (s)to the Whole Plane214
4.3 The Functioal Equation216
4.4 The Zeros of the Zeta Functaion218
5 Normal Families 219
5.1 Equicontinuity219
5.2 Normality and Compactness220
5.3 Arzela's Theorem222
5.4 Families of Analytic Functions223
5.5 The Claaical Definition225
CHAPTER 6 CONFORMAL MAPPUNG. DIRICHLET'S PROBLEM229
1 The Riemann Mapping Throrem229
1.1 Statement and Proof229
1.2 Boundary Behavior232
1.3 Use of the Reflection Principle233
1.4 Analytic Arcs234
2 Conformal Mapping of Polygons235
2.1 The Behavior at an Angle 235
2.2 The Schwarz-Christoffel Formula236
2.3 Mapping on a Rectangle238
2.4 The Triangle Functions of Schwarz241
3 A Closer Look at Harmonic Functions241
3.1 Functions with the Mean-value Property242
3.2 Harnack's Principle 243
4 The Dirichlet Problem245
4.1 Subharmonic Functions245
4.2 Solution of Dirchlet's Problem248
5 Canonical Mappings of Multiply Connected Regions251
5.1 Harmonic Measures252
5.2 Green's