Order ( IF 0.4 ) Pub Date : 2021-03-20 , DOI: 10.1007/s11083-021-09556-5 Anthony W. Hager , Philip Scowcroft
Within archimedean ℓ-groups, “G ∈ SW∗” means there are H with strong unit (H ∈ W∗) and an embedding G ≤ H. A. Theorem (6.1). For X a Tychonoff space (or completely regular locale), C(X) ∈ SW∗ iff X is pseudocompact (which means C(X) ∈ W∗). But any G ∈ SW∗ embeds into various C(X), and any C(X) contains many H ∈ W∗. We define cardinal invariants \(\mathfrak {b}G\), \(\mathfrak {d}G\), λG which generalize respectively, the bounding and dominating numbers for \(\mathbb {R}^{\mathbb {N}}\), \(\mathfrak {b}\) and \(\mathfrak {d}\), and the π-weight of a topological space. B. Theorem (6.3, 7.5). SupposeG ≤ C(X), and X contains densely \(\bigcup _{I} X_{i}\), the Xi compact. Then G ∈ SW∗ if either (|I| = ω and \(\mathfrak {d}G < \mathfrak {b}\)) or (\(|I| < \mathfrak {b}\) and \(\mathfrak {d}G = \omega \)). This “\(\omega , \mathfrak {b}\) symmetry” fades a bit in the following, where \(\mathfrak {p}\) is the pseudo-intersection number for \(\mathbb {R}^{\mathbb {N}}\) (\(\mathfrak {p} \le \mathfrak {b}\), with = under Martin’s Axiom). C. Theorem (8.2). G ∈ SW∗ if either \((\mathfrak {d}G = \omega \) and \(\lambda G < \mathfrak {b}\)) or (\(\mathfrak {d}G < \mathfrak {p}\) andλG = ω). Examples (§9) show limits on the hypotheses in B and C.
中文翻译:
将一个强大的部队与一个阿基米德格子定律团体联系在一起
内阿基米德ℓ -基团,“ G ^ ∈小号W¯¯ * ”的意思有ħ具有很强的单元(ħ ∈ w ^ *)和一个嵌入ģ ≤ ħ。A.定理(6.1)。 对于 X 一吉洪诺夫空间(或完全正区域),Ç(X)∈小号W¯¯ * 当且仅当 X 是pseudocompact(这意味着 Ç(X)∈ w ^ *)。但是,任何摹∈小号w ^ *嵌入到各种Ç(X),以及任何Ç(X)含有许多ħ ∈ w ^ *。我们定义基数不变量\(\ mathfrak {B} g ^ \) ,\(\ mathfrak {d} g ^ \) ,λ ģ分别一概而论,边界和用于控制数\(\ mathbb {R} ^ {\ mathbb { N}} \),\(\ mathfrak {b} \)和\(\ mathfrak {d} \)以及拓扑空间的π权重。B.定理(6.3,7.5)。 假设ģ ≤ Ç(X),并且 X 包含密集的 \(\ bigcup _ {I} X_ {i} \),即 X i 压缩。然后 ģ ∈小号W¯¯ * 如果任一(|我| = ω 和 \(\ mathfrak {d} g ^ <\ mathfrak {B} \) )或(\(| I | <\ mathfrak {B} \) 和 \( \ mathfrak {d} G = \ omega \))。这种“ \(\ omega,\ mathfrak {b} \)对称性”在下面逐渐淡出,其中\(\ mathfrak {p} \)是\(\ mathbb {R} ^ {\ mathbb {N}} \)(\(\ mathfrak {p} \ le \ mathfrak {b} \),在Martin's Axiom下带有=)。C.定理(8.2)。 ģ ∈小号W¯¯ * 如果任 \((\ mathfrak {d} G = \欧米加\) 和 \(\拉姆达ģ<\ mathfrak {B} \) )或(\(\ mathfrak {d} g ^ <\ mathfrak { p} \) 和λ ģ = ω)。示例(第9节)显示了B和C中假设的限制。