Nonlinear Functional Analysis

Front Cover
Springer Science & Business Media, Nov 11, 2013 - Mathematics - 450 pages
topics. However, only a modest preliminary knowledge is needed. In the first chapter, where we introduce an important topological concept, the so-called topological degree for continuous maps from subsets ofRn into Rn, you need not know anything about functional analysis. Starting with Chapter 2, where infinite dimensions first appear, one should be familiar with the essential step of consider ing a sequence or a function of some sort as a point in the corresponding vector space of all such sequences or functions, whenever this abstraction is worthwhile. One should also work out the things which are proved in § 7 and accept certain basic principles of linear functional analysis quoted there for easier references, until they are applied in later chapters. In other words, even the 'completely linear' sections which we have included for your convenience serve only as a vehicle for progress in nonlinearity. Another point that makes the text introductory is the use of an essentially uniform mathematical language and way of thinking, one which is no doubt familiar from elementary lectures in analysis that did not worry much about its connections with algebra and topology. Of course we shall use some elementary topological concepts, which may be new, but in fact only a few remarks here and there pertain to algebraic or differential topological concepts and methods.
 

Contents

Topological Degree in Finite Dimensions
1
Borsuks Theorem
21
Concluding Remarks
27
Topological Degree in Infinite Dimensions
35
Compact Maps
55
Set Contractions
68
Concluding Remarks
87
Monotone and Accretive Operators
95
Solutions in Cones
217
Solutions in Cones
238
Approximate Solutions
256
AProper Maps and Galerkin for Differential Equations
267
Multis
278
Multis and Compactness
299
Extremal Problems
319
Extrema Under Constraints
332

Monotone Operators on Banach Spaces
111
Accretive Operators
123
Concluding Remarks
133
Implicit Functions and Problems at Resonance
146
Problems at Resonance
172
Fixed Point Theory
186
Fixed Point Theorems Involving Compactness
203
Critical Points of Functionals
349
Bifurcation
378
Global Bifurcation
398
Further Topics in Bifurcation Theory
411
Epilogue
426
Symbols
445
Copyright

Other editions - View all

Common terms and phrases

Bibliographic information