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Positive-moment problems in abstract measure spaces

Published online by Cambridge University Press:  24 October 2008

H. P. Rogosinski
Affiliation:
University College, Swansea

Extract

In this paper we continue the investigation of positive-moment problems, begun in (4). For an arbitrary index set A we consider a family (fα)α ∈ A of measurable real-valued functions on a measure-space (X, µ). We suppose throughout that

where (Xm) is an increasing sequence of measurable subsets of X and where, for each α in A and each m, fα is µ-integrable over Xm. Let (сα)α ∈ A be a given family of real numbers. We consider the following restricted positive-moment problem: does there exist a measurable function g on X such that 0 ≤° g ≤° 1 and such that

for every α in A? (Here the symbol ‘≤°’ indicates that the relation ≤ holds almost everywhere with respect to µ on X. Symbols ‘ = °, <°, …’ are used similarly.) If such a g exists we call (сα)α ∈ A a moment family for the problem:

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1975

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References

REFERENCES

(1)Dunford, N. and Schwahtz, J. T.Linear Operators Part 1 (New York, Interscience, 1958).Google Scholar
(2)Karlin, S. and Shapley, L. S.Geometry of Moment Spaces. Mem. Amer. Math. Soc. 12 (1953).Google Scholar
(3)Kelley, J. L.General Topology (New York, D. van Nostrand, 1955).Google Scholar
(4)Rogosinski, H. P.Finite positive-moment problems. J. London. Math. Soc. 43 (1968), 658666.CrossRefGoogle Scholar
(5)Rogosinski, W. W.Moments of non-negative mass. Proc. Royal Soc. A 245 (1958), 127.Google Scholar
(6)Rogosinski, W. W.Volume and Integral (Edinburgh, Oliver and Boyd, 1952).Google Scholar