Volume no :5, Issue no: 1, May 2010

ON SHY SETS IN RADON METRIC GROUPS

Author's: Gogi R. Pantsulaia
Pages: [149] - [185]
Received Date: February 11, 2010
Submitted by:

Abstract

Let G be a complete metric group and be such a subgroup of its Borel automorphisms group which contains all left and right shifts of the G. We introduce notions of cm and shy sets and demonstrate that they constitute a ideal and coincide in Radon metric groups. This result extends main results established in [6], [13], [20]. For a Borel probability measure in a Polish group G, we construct the generator of shy sets which is quasi-finite, whenever the is a quasi-generator. Using Okazaki-Takahashi result [23], we prove that, if a group of admissible translations (in the sense of quasi-invariance) for a Borel probability in a Polish topological vector space is thick, then the generator of shy (equivalently, shy) sets is quasi-finite. For such a Borel measure we construct a quasi-finite semi-finite translation-invariant Borel measure which is equivalent to the generator Also, we show that Okazaki’s dichotomy [22] is not valid for generators of shy sets in By using technique of cm and shy sets, we solve negatively a certain problem posed by Fremlin in [9].

Keywords

generator of shy sets, Haar null set, shy set, Polish topological vector space.