文档介绍：QUANTUMCOSMOLOGY
AND
BABYUNIVERSES
by
SteveWeinberg
Published by
World Scientific Publishing Co. Pte. Ltd.
POBox 128, Farrer Road, Singapore 9128
USA office: Suite IB, 1060 Main Street, River Edge, NJ 07661
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QUANTUM COSMOLOGY AND BABY UNIVERSES
Copyright © 1991 by World Scientific Publishing Co. Pte. Ltd.
All righJs reserved. This book, orparts thereof, may not be reproduced in anyform
orbyanymeans, electronicormechanical, includingphotocopying, recording orany
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written permissionjrom the Publisher.
ISBN 981-02-0345-4
981-02-0346-2 (Pbk)
Printed in Singapore by Utopia Press.
v
PREFACE
Quantum gravity is notoriously a subject where problems vastly outnumber
results. This is no surprise at short distances, on the order of the Planck length,
where most of us expect quantum fluctuations in the metric to cause space-time
itself to lose its meaning and gravity to be subsumed (along with the other so-called
fundamental interactions) into some prehensive, consistent, and radical
theory. However, even at larger scales, where one would naively expect quantum
corrections to be small and controllable, reasonable people disagree not only on what
are the right answers but also on what are the right questions. Recently there has
been a flurry of activity in this area, inspired both by the importation of ideas from
string theory and by speculations about connections between topology-changing
quantum fluctuations and the vanishing of the cosmological constant. This last was
the focus of the Seventh Jerusalem Winter School, on "Quantum Cosmology and
Baby Universes", held from December 27 1989 to January 5 1990.
Lectures were given by S. Coleman (Harvard), J. Halliwell (.), J. Har•
tle (University of California, Santa Barbara), S. Hawking (Cambridge), A. Stro•
minger (University of Cal