Open-Invariant Measures and the Covering Number of Sets
β Scribed by Hermann Haase
- Publisher
- John Wiley and Sons
- Year
- 1987
- Tongue
- English
- Weight
- 598 KB
- Volume
- 134
- Category
- Article
- ISSN
- 0025-584X
No coin nor oath required. For personal study only.
β¦ Synopsis
A reault of J. MYCIELSIZI ssp that on every metric space (X, e) with a non-empty compact thick set C X there exists a repbr open-invsriant BOREL measure p with p(C) = 1. p is mlled open-invariant if p(A) = p(B) for open isometric sets A, 3 X. We relste this result to the notion of a Hrrwm~-S~~omms~ measure and give s new independent existence proof for euch an open-invariant measure p on s compact metric apace (X, e). This proof worka by induction, the well-known metric outer maonstruction of C ~~D O R Y : H A W S D O R S S and s new property of the covering number N(X, q) of X.
π SIMILAR VOLUMES
Let the points PI, P2 .... , P~ be given in the plane such that there are no three on a line. Then there exists a point of the plane which is contained in at least n3/27 (open) P~P~Pk triangles. This bound is the best possible.
## Daniels (1988) started an investigation of the duality between selection hypotheses for X β R and selection hypotheses for the Pixley-Roy space of X. Daniels, Kunen and Zhou (1994) introduced the "open-open game". We extend some results of Daniels (1988) by connecting the relevant selection hyp