Real Analysis
PURE AND APPLIED MATHEMATICS
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AKIVIS and GOLDBERGConformal Differential Geometry and Its Generalizations
ALLEN and ISAACSONNumerical Analysis for Applied Science
ARTINGeometric Algebra
AZIZOV and IOKHVIDOVLinear Operators in Spaces with an Indefinite Metric
BERMAN, NEUMANN, and STERNNonnegative Matrices in Dynamic Systems
BOYARINTSEVMethods of Solving Singular Systems of Ordinary Differential Equations
BURKLebesgue Measure and Integration: An Introduction
CARTERFinite Groups of Lie Type
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DUNFORD and SCHWARTZLinear Operators
Part 1-General Theory
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FOLLANDReal Analysis: Modem Techniques and Their Applications
FRLICHER and KRIEGLLinear Spaces and Differentiation Theory
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NAYFEH and MOOKNonlinear Oscillations
PANDEYThe Hilbert Transform of Schwartz Distributions and Applications
PETKOVGeometry of Reflecting Rays and Inverse Spectral Problems
PRENTERSplines and Variational Methods
RAOMeasure Theory and Integration
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Library of Congress Cataloging-in-Publication Data:
Folland, Gerald B.
Real analysis : modern techniques and their applications / Gerald B. Folland. 2nd ed.
p. cm. (Pure and applied mathematics)
A Wiley-Interscience publication.
Includes bibliographical references and index.
ISBN 0-471-31716-0 (cloth : alk. paper)
1. Mathematical analysis. 2. Functions of real variables.
I. Title. II. Series: Pure and applied mathematics (John Wiley & Sons: Unnumbered)
QA300.F67 1999
515dc21
9837260
To the memory of my mother and father
Helen B. Folland
and
Harold F. Folland
Preface
The name real analysis is something of an anachronism. Originally applied to the theory of functions of a real variable, it has come to encompass several subjects of a more general and abstract nature that underlie much of modern analysis. These general theories and their applications are the subject of this book, which is intended primarily as a text for a graduate-level analysis course. Chapters 1 through 7 are devoted to the core material from measure and integration theory, point set topology, and functional analysis that is a part of most graduate curricula in mathematics, together with a few related but less standard items with which I think all analysts should be acquainted. The last four chapters contain a variety of topics that are meant to introduce some of the other branches of analysis and to illustrate the uses of the preceding material. I believe these topics are all interesting and important, but their selection in preference to others is largely a matter of personal predilection.
The things one needs to know in order to read this book are as follows:
First and foremost, the classical theory of functions of a real variable: limits and continuity, differentiation and (Riemann) integration, infinite series, uniform convergence, and the notion of a metric space.
The arithmetic of complex numbers and the basic properties of the complex exponential function