Hostname: page-component-848d4c4894-hfldf Total loading time: 0 Render date: 2024-05-18T02:34:18.840Z Has data issue: false hasContentIssue false

On the selection of non-σ-finite subsets

Published online by Cambridge University Press:  26 February 2010

D. G. Larman
Affiliation:
University College, London.
Get access

Extract

Let A be a subset of a compact metric space Ω, and suppose that A has non-σ-finite h-measure, where h is some Hausdorff function. The following problem was suggested to me by Professor C. A. Rogers:

If A is analytic, is it possible to construct 2ℵodisjoint closed subsets of A which also have non-σ-finite h-measure?

At this level of generality the problem, like others which involve selection of subsets, appears to offer some difficulty. Here we prove two results which were motivated by it.

Type
Research Article
Copyright
Copyright © University College London 1967

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Larman, D. G., “A new theory of dimension”, Proc. London Math. Soc. (3), 17 (1967), 178192.Google Scholar
2.Larman, D. G., “On Hausdorff measure in finite-dimensional compact metric spaces”, Proc. London Math. Soc. (3), 17 (1967), 193206.Google Scholar
3.Besicovitch, A. S., “Concentrated and rarified sets of points”, Acta Mathematica, 62 (1934), 289300.Google Scholar
4.Rogers, C. A., “Sets non-σ-finite for Hausdorff measures”, Mathematika, 9 (1962), 95103.CrossRefGoogle Scholar
5.Besicovitch, A. S., “A theorem on s-dimensional sets of points”, Proc. Cambridge Phil. Soc., 38 (1942), 2427.Google Scholar
6.Sion, M. and Sjerve, D., “Approximation properties of measures generated by continuous set functions”, Mathematika, 9 (1962), 145156.Google Scholar