TY - JOUR
T1 - Strongly almost disjoint familes, revisited
AU - Hajnal, A.
AU - Juhász, I.
AU - Shelah, S.
PY - 2000
Y1 - 2000
N2 - The relations M(K, λ, μ) → B [resp. B(σ)] meaning that if A ⊂ [K]λ with \A\ = K is μ-almost disjoint then A has property B [resp. has a σ-transversal] had been introduced and studied under GCH in [EH]. Our two main results here say the following: Assume GCH and let ρ be any regular cardinal with a supercompact [resp. 2-huge] cardinal above ρ. Then there is a ρ-closed forcing P such that, in VP, we have both GCH and M(ρ(+ρ+1), ρ+, ρ) →B [resp. M(ρ(+ρ+1), λ, ρ) → B(ρ+) for all λ ≤ ρ(+ρ+1)]. These show that, consistently, the results of [EH] are sharp. The necessity of using large cardinals follows from the results of [Ko], [HJSh] and [BDJShSz].
AB - The relations M(K, λ, μ) → B [resp. B(σ)] meaning that if A ⊂ [K]λ with \A\ = K is μ-almost disjoint then A has property B [resp. has a σ-transversal] had been introduced and studied under GCH in [EH]. Our two main results here say the following: Assume GCH and let ρ be any regular cardinal with a supercompact [resp. 2-huge] cardinal above ρ. Then there is a ρ-closed forcing P such that, in VP, we have both GCH and M(ρ(+ρ+1), ρ+, ρ) →B [resp. M(ρ(+ρ+1), λ, ρ) → B(ρ+) for all λ ≤ ρ(+ρ+1)]. These show that, consistently, the results of [EH] are sharp. The necessity of using large cardinals follows from the results of [Ko], [HJSh] and [BDJShSz].
KW - σ-transversal
KW - Property B
KW - Strongly almost disjoint family
UR - http://www.scopus.com/inward/record.url?scp=0040200041&partnerID=8YFLogxK
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0040200041
SN - 0016-2736
VL - 163
SP - 13
EP - 23
JO - Fundamenta Mathematicae
JF - Fundamenta Mathematicae
IS - 1
ER -