A metamathematical condition equivalent to the existence of a complete left invariant metric for a Polish group
نویسنده
چکیده
Strengthening a theorem of Hjorth this paper gives a new characterization of which Polish groups admit compatible complete left invariant metrics. As a corollary it is proved that any Polish group without a complete left invariant metric has a continuous action on a Polish space whose associated orbit equivalence relation is not essentially countable.
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ورودعنوان ژورنال:
- J. Symb. Log.
دوره 71 شماره
صفحات -
تاریخ انتشار 2006