Abstract
A topological Hausdorff space X is sequentially linearly Lindelöf if for every uncountable regular cardinal κ≤w(X) and every A⊆X of cardinality κ there exists B⊆A of cardinality κ which converges to a point. We prove that the existence of a good (μ,λ)-scale for a singular cardinal μ of countable cofinality and a regular λ>μ implies the existence of a sequentially linearly Lindelöf space of cardinality λ and weight μ which is not Lindelöf.Corollaries of the main result are: (1) it is consistent to have linearly Lindelöf non-Lindelöf spaces below the continuum; (2) it is consistent to have a realcompact linearly Lindelöf non-Lindelöf space below 2אω; (3) it is consistent to have a Dowker topology on אω+1 in which every subset of cardinality אn, n>0, has a converging subset of the same cardinality; (4) the nonexistence of sequentially linearly Lindelöf non-Lindelöf spaces implies the consistency of large cardinals.
Original language | English |
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Pages (from-to) | 135-144 |
Number of pages | 10 |
Journal | Topology and its Applications |
Volume | 128 |
Issue number | 2-3 |
DOIs | |
State | Published - 15 Feb 2003 |
Keywords
- Complete accumulation
- Inner models
- Large cardinals
- Linearly Lindelöf spaces
- PCF-theory
- Realcompact spaces
- Singular cardinals
- Square principle
ASJC Scopus subject areas
- Geometry and Topology