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Second-order differential expressions whose squares are limit-3

Published online by Cambridge University Press:  14 February 2012

M. S. P. Eastham
Affiliation:
Chelsea College, University of London
A. Zettl
Affiliation:
Northern Illinois University, De Kalb, Illinois

Synopsis

Second-order expressions –d2/dx2+q whose squares are of limit-3 type are constructed. The construction is simpler than others in the literature. The function q can be chosen to be infinitely differentiable and decreasing and to satisfy q(x)≧ –x2(log x)2+ε (x→∞) for a given ε>0.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1977

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