论文标题
关于与强度零的理想相关的基本特征
On cardinal characteristics associated with the strong measure zero ideal
论文作者
论文摘要
令$ \ MATHCAL {SN} $为强度的零$σ$ - 理想。我们证明了为$ \ mathrm {cof}(\ mathcal {sn})$提供界限的结果,这意味着yorioka对强度零的辅助性的表征。此外,我们使用强制矩阵迭代来构建满足的ZFC模型$ \ MATHRM {add}(\ Mathcal {sn})= \ Mathrm {Cov}(\ Mathcal {sn})<\ Mathrm {non}(\ Mathcal {SN})
Let $\mathcal{SN}$ be the strong measure zero $σ$-ideal. We prove a result providing bounds for $\mathrm{cof}(\mathcal{SN})$ which implies Yorioka's characterization of the cofinality of the strong measure zero. In addition, we use forcing matrix iterations to construct a model of ZFC that satisfies $\mathrm{add}(\mathcal{SN})=\mathrm{cov}(\mathcal{SN})<\mathrm{non}(\mathcal{SN})<\mathrm{cof}(\mathcal{SN})$.