TY - JOUR
T1 - Ultrafilters and almost disjoint sets
AU - Prikry, Karel
PY - 1974/9
Y1 - 1974/9
N2 - Let μκ denote the space of uniform ultrafilters on κ, and let λ be a cardinal. Uε{lunate}μκ is said to be a λ-point of μκ if U is a boundary point of λ pairwise disjoint open subsets of μκ. We prove that if κ is a successor cardinal, 2κ= κ+, and Kurepa's hypothesis for κ holds, then each U ε{lunate} μκ is a 2κ-point of μκ.
AB - Let μκ denote the space of uniform ultrafilters on κ, and let λ be a cardinal. Uε{lunate}μκ is said to be a λ-point of μκ if U is a boundary point of λ pairwise disjoint open subsets of μκ. We prove that if κ is a successor cardinal, 2κ= κ+, and Kurepa's hypothesis for κ holds, then each U ε{lunate} μκ is a 2κ-point of μκ.
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U2 - 10.1016/0016-660X(74)90026-9
DO - 10.1016/0016-660X(74)90026-9
M3 - Article
AN - SCOPUS:49549154866
SN - 0016-660X
VL - 4
SP - 269
EP - 282
JO - General Topology and its Applications
JF - General Topology and its Applications
IS - 3
ER -