Almost Periodic Type Functions and Ergodicity

The theory of almost periodic functions was first developed by the Danish mathematician H. Bohr during 1925-1926. Then Bohr's work was substantially extended by S. Bochner, H. Weyl, A. Besicovitch, J. Favard, J. von Neumann, V. V. Stepanov, N. N. Bogolyubov, and oth ers. Generalization of the classical theory of almost periodic functions has been taken in several directions. One direction is the broader study of functions of almost periodic type. Related this is the study of ergodic ity. It shows that the ergodicity plays an important part in the theories of function spectrum, semigroup of bounded linear operators, and dynamical systems. The purpose of this book is to develop a theory of almost pe riodic type functions and ergodicity with applications-in particular, to our interest-in the theory of differential equations, functional differen tial equations and abstract evolution equations. The author selects these topics because there have been many (excellent) books on almost periodic functions and relatively, few books on almost periodic type and ergodicity. The author also wishes to reflect new results in the book during recent years. The book consists of four chapters. In the first chapter, we present a basic theory of four almost periodic type functions. Section 1. 1 is about almost periodic functions. To make the reader easily learn the almost periodicity, we first discuss it in scalar case. After studying a classical theory for this case, we generalize it to finite dimensional vector-valued case, and finally, to Banach-valued (including Hilbert-valued) situation.

List of contents

1 Almost periodic type functions.- 1.1.- 1.2 Asymptotically almost periodic functions.- 1.3 Weakly almost periodic functions.- 1.4 Approximate theorem and applications.- 1.5 Pseudo almost periodic functions.- 1.6 Converse problems of Fourier expansions.- 1.7 Almost periodic type sequences.- 2 Almost periodic type differential equations.- 2.1 Linear differential equations.- 2.2 Partial differential equations.- 2.3 Means, introversion and nonlinear equations.- 2.4 Regularity and exponential dichotomy.- 2.5 Equations with piecewise constant argument.- 2.6 Equations with unbounded forcing term.- 2.7 Almost periodic structural stability.- 3 Ergodicity and abstract differential equations.- 3.1 Ergodicity and regularity.- 3.2 Ergodicity and nonlinear equations.- 3.3 Semigroup of operators and applications.- 3.4 Delay differential equations.- 3.5 Spectrum of functions.- 3.6 Abstract Cauchy Problems.- 4 Ergodicity and averaging methods.- 4.1 Ergodicity and its properties.- 4.2 Quantitative theory.- 4.3 Perturbations of noncritical linear systems.- 4.4 Qualitative theory of averaging methods.- 4.5 Averaging methods for functional equations.- Notations.

Summary

The theory of almost periodic functions was first developed by the Danish mathematician H. Bohr during 1925-1926. Then Bohr's work was substantially extended by S. Bochner, H. Weyl, A. Besicovitch, J. Favard, J. von Neumann, V. V. Stepanov, N. N. Bogolyubov, and oth­ ers. Generalization of the classical theory of almost periodic functions has been taken in several directions. One direction is the broader study of functions of almost periodic type. Related this is the study of ergodic­ ity. It shows that the ergodicity plays an important part in the theories of function spectrum, semigroup of bounded linear operators, and dynamical systems. The purpose of this book is to develop a theory of almost pe­ riodic type functions and ergodicity with applications-in particular, to our interest-in the theory of differential equations, functional differen­ tial equations and abstract evolution equations. The author selects these topics because there have been many (excellent) books on almost periodic functions and relatively, few books on almost periodic type and ergodicity. The author also wishes to reflect new results in the book during recent years. The book consists of four chapters. In the first chapter, we present a basic theory of four almost periodic type functions. Section 1. 1 is about almost periodic functions. To make the reader easily learn the almost periodicity, we first discuss it in scalar case. After studying a classical theory for this case, we generalize it to finite dimensional vector-valued case, and finally, to Banach-valued (including Hilbert-valued) situation.

Additional text

From the reviews:

"In this monograph, the function classes considered are; Bohr almost periodic … asymptotic ap AAP, Eberlein weakly ap WAP … and X a Banach space. These are introduced and discussed in some detail; then the author addresses their application to the asymptotic study of solutions of differential equations … . One should be grateful for the wealth of material presented, collecting, unifying and sometimes generalizing many recent results. Consequently, the book can serve as an introduction … and it would be especially good for seminars." (Hans F. Günzler, Zentralblatt MATH, Vol. 1068 (19), 2005)

Report

From the reviews:

"In this monograph, the function classes considered are; Bohr almost periodic ... asymptotic ap AAP, Eberlein weakly ap WAP ... and X a Banach space. These are introduced and discussed in some detail; then the author addresses their application to the asymptotic study of solutions of differential equations ... . One should be grateful for the wealth of material presented, collecting, unifying and sometimes generalizing many recent results. Consequently, the book can serve as an introduction ... and it would be especially good for seminars." (Hans F. Günzler, Zentralblatt MATH, Vol. 1068 (19), 2005)

Product details

• Authors: Zhang Chuanyi, Zhang Chuanyi
• Publisher: Springer Netherlands
• Languages: English
• Product format: Hardback
• Released: 26.06.2009
• EAN: 9781402011580
• ISBN: 978-1-4020-1158-0
• No. of pages: 355
• Weight: 699 g
• Illustrations: XI, 355 p.
• Subjects: Natural sciences, medicine, IT, technology > Mathematics > Analysis; B, Mathematics and Statistics, Functional Analysis, Ordinary Differential Equations, Partial Differential Equations, Abstract Harmonic Analysis, Harmonic analysis, Differential calculus & equations, Differential equations, Functional analysis & transforms, Fourier Analysis