THE MINKOWSKI MULTIDIMENSIONAL PROBLEM A. V. Pogorelov with an introduction by Louis Nirenberg THE MINKOWSKI MULTIDIMENSIONAL PROBLEM ALEKSEY V. POGORELOV The Minkowski problem is that of finding a closed convex surface in R3 whose Gaussian curvature is a given positive function K of the exterior unit normal; K necessarily satisfies the three conditions /M T1 (ö*o(ö = 0 /=1,2,3 where integration is over the unit sphere. In addition to the regular solu tion of the Minkowski problem, the book covers a number of related questions in geometry and the theory of differential equations with partial derivatives. In particu lar, it considers the general problem of a closed convex hypersurface with a prescribed function of curva ture of any degree. The generalized solutions of the multidimensional analogue of the Monge-Ampere equation are studied and their regu larity under certain conditions is proved. The Dirichlet problem is solved. Also, improper convex affine hyperspheres are discussed and proved to be elliptic para boloids if they are full. In the words of the introducer, Professor Louis Nirenberg of the Courant Institute of Mathematical Sciences, “This book will introduce to the reader some beautiful geo metric problems and a variety of interesting, deep, techniques for ob taining a priori estimates for elliptic (continued on inside back flap) Li THE MINKOWSKI MULTIDIMENSIONAL PROBLEM SCRIPTA SERIES IN MATHEMATICS Tikhonov and Arsenin • Solutions of Ill-Posed Problems, 1977 Rozanov • Innovation Processes, 1977 Pdgorelov • The Minkowski Multidimensional Problem, 1978 Kolchin, Sevast'yanov, and Chist'yakov • Random Allocations, 1978 Boltyanskiy • Hilbert’s Third Problem, 1978 THE MINKOWSKI MULTIDIMENSIONAL PROBLEM Aleksey Vasu/yevich Pogorelov USSR Academy of Sciences Translated by Vladimir Oliker, University of Iowa and introduced by Louis Nirenberg, Courant Institute of Mathematical Sciences 1978 V. H. WINSTON & SONS Washington, D.C. A HALSTED PRESS BOOK JOHN WILEY & SONS New York Toronto London Sydney Copyright © 1978, by V. H. Winston & Sons, a Division of Scripta Technica, Inc. All rights reserved. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher. V. H. Winston & Sons, a Division of Scripta Technica, Inc., Publishers 1511 K Street, N.W., Washington, D.C. 20005 Distributed solely by Halsted Press, a Division of John Wiley & Sons, Inc. Library of Congress Cataloging in Publication Data Pogorelov, Aleksei Vasil’evich. The Minkowski multidimensional problem. (Scripta series in mathematics) Translation of Mnogomemaía problema Minkovskogo. Bibliography: p. I. Convex surfaces. 2. Spaces, Generalized. I. Title. II. Series. QA643.P73813 516\362 77-16680 ISBN 0-470-99358-8 Composition by Isabelle Sneeringer, Scripta Technica, Inc. CONTENTS INTRODUCTORY COMMENTARY....................................... I PREFACE TO THE AMERICAN EDITION ........................ 3 FOREWORD................................................................................ 5 INTRODUCTION ...................................................................... 7 §1. Convex Bodies and Hypersurfaces in En .................. 9 §2. Generalized Solution of the Minkowski Problem . . 22 §3. Regular Solution of Minkowski’s Problem ............. 32 §4. Generalization of Minkowski’s Problem .................. 50 §5. Multidimensional Analog of the Monge-Ampère Equation ................................................................... 66 §6. On Improper Convex Affine Hyperspheres ........... 89 BIBLIOGRAPHY ................................................................... 105 V INTRODUCTORY COMMENTARY The Minkowski problem is that of finding a closed convex surface in R3 whose Gaussian curvature is a given positive function K of the exterior unit normal; K necessarily satisfies the three conditions J&K“1 «)Л0(8 = 0 /=1,2,3 where integration is over the unit sphere. In case A' is a smooth function the problem has a smooth solution and a presentation of this result is contained in the, now classic, book [8] by the author. The Minkowski problem has a direct extension for closed convex hypersurfaces in Rn. However, after the result in R39 it still took a number of years before the corresponding higher dimensional result was established—in a series of papers by A.V. Pogorelov (in the bibliography). This book presents a detailed treatment of the results described in those papers as well as generalizations of the Minkowski problem. Analytically, the Minkowski problem involves solving a highly nonlinear partial differential equation of Monge-Ampère type. An example of such an equation, for a convex function u(xl,... ,xn) I 2 INTRODUCTORY COMMENTARY defined in a domain in Rn is where ф(х) is a given position function. To prove the existence of solutions of such equations, satisfying some boundary conditions, is no easy task. It involves finding a priori estimates for solutions and their derivatives up to third order. These estimates are all due to the author. In deriving bounds for the third derivatives he makes use of ideas of E. Calabi in [10]. This book also contains Pogorelov’s proof of the conjecture (established previously for n < 5), that the only convex function satisfying (*) in all of Rn with ф = I is a quadratic. This book will introduce to the reader some beautiful geometric problems and a variety of interesting, deep, techniques for obtain ing cl priori estimates for elliptic equations—written by a master in the subject. It should serve as a basic reference for many years. Attention of the reader should also be drawn to the recent papers by S. Y. Cheng and S. T. Yau on these topics: On the regularity of the solution of the и-dimensional Minkowski problem, Comm. Pure Appl Math., (1976), 29, pp. 495-516. On the regularity of the Monge-Ampère equation det = F(x, u) \Ъх1ЪхЧ v f Comm. Pure AppL Math, (1977), 30, pp. 41-68. Louis Nirenberg Courant Institute of Mathematical Sciences November 1977