1. CJM 2012 (vol 64 pp. 1182)
||PFA$(S)[S]$: More Mutually Consistent Topological Consequences of $PFA$ and $V=L$|
Extending the work of Larson and Todorcevic,
we show there
is a model of set theory in which normal spaces are collectionwise
Hausdorff if they are either first countable or locally compact, and
yet there are no first countable $L$-spaces or compact
$S$-spaces. The model is one of the form PFA$(S)[S]$, where $S$
is a coherent Souslin tree.
Keywords:PFA$(S)[S]$, proper forcing, coherent Souslin tree, locally compact, normal, collectionwise Hausdorff, supercompact cardinal
Categories:54A35, 54D15, 54D20, 54D45, 03E35, 03E57, 03E65
2. CJM 2009 (vol 61 pp. 604)
||First Countable Continua and Proper Forcing |
Assuming the Continuum Hypothesis,
there is a compact, first countable, connected space of weight $\aleph_1$
with no totally disconnected perfect subsets.
Each such space, however, may be destroyed by
some proper forcing order which does not add reals.
Keywords:connected space, Continuum Hypothesis, proper forcing, irreducible map