Jörg Brendle, Miguel A. Cardona, Diego A. Mejía
2023.9.5Journal of Mathematical Logic
Resumen
Let $\mathcal{SN}$ be the $\sigma$-ideal of the strong measure zero sets of reals. We present general properties of forcing notions that allow to control of the additivity of $\mathcal{SN}$ after finite support iterations. This is applied to force that the four cardinal characteristics associated with $\mathcal{SN}$ are pairwise different: \[\mathrm{add}(\mathcal{SN})<\mathrm{cov}(\mathcal{SN})<\mathrm{non}(\mathcal{SN})<\mathrm{cof}(\mathcal{SN}).\] Furthermore, we construct a forcing extension satisfying the above and Cicho\'n's maximum (i.e.\ that the non-dependent values in Cicho\'n's diagram are pairwise different).
Formato de cita
BRENDLE, Jörg; CARDONA, Miguel A.; MEJÍA, Diego A. Separating cardinal characteristics of the strong measure zero ideal [preprint]. arXiv, 2023. arXiv:2309.01931.