First countable spaces without point-countable -bases
István Juhász,
Lajos Soukup and Zoltán Szentmiklóssy
We answer several questions of V. Tkacuk from [Point-countable -bases in first countable and similar spaces,
Fund. Math. 186 (2005), pp. 55-69.] by showing that
- there is a ZFC example of a first countable, 0-dimensional Hausdorff space
with no point-countable -base (in fact, the order of any
-base of the space is at least
);
- if there is a -Suslin line then there is a first
countable GO space of cardinality in which the order of
any -base is at least ;
- it is consistent to have a first
countable, hereditarily Lindelöf regular space having uncountable
-weight and as a caliber (of course, such a space
cannot have a point-countable -base).
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2000 Mathematics Subject Classification:
Primary: , Secondary:
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