On cardinal sequences of length less than omega3
We prove the following consistency result for cardinal sequences of length $<\omega_3$ : if GCH holds and $\lambda \geq \omega_2$ is a regular cardinal, then in some cardinal-preserving generic extension $2^\omega=\lambda$ and for every ordinal $\eta<\omega_3$ and every sequence $f=\left\langl...
| Authors: | , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2019 |
| Country: | España |
| Institution: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repository: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/193559 |
| Online Access: | https://hdl.handle.net/2445/193559 |
| Access Level: | Open access |
| Keyword: | Nombres cardinals Teoria de conjunts Àlgebra de Boole Dispersió (Matemàtica) Cardinal numbers Set theory Boolean algebras Scattering (Mathematics) |
| Summary: | We prove the following consistency result for cardinal sequences of length $<\omega_3$ : if GCH holds and $\lambda \geq \omega_2$ is a regular cardinal, then in some cardinal-preserving generic extension $2^\omega=\lambda$ and for every ordinal $\eta<\omega_3$ and every sequence $f=\left\langle\kappa_\alpha: \alpha<\eta\right\rangle$ of infinite cardinals with $\kappa_\alpha \leq \lambda$ for $\alpha<\eta$ and $\kappa_\alpha=\omega$ if $\operatorname{cf}(\alpha)=\omega_2$, we have that $f$ is the cardinal sequence of some LCS space. Also, we prove that for every specific uncountable cardinal $\lambda$ it is relatively consistent with ZFC that for every $\alpha, \beta<\omega_3$ with $\operatorname{cf}(\alpha)<\omega_2$ there is an LCS space $Z$ such that $\left.\operatorname{CS}(Z)=\langle\omega\rangle_\alpha \gamma \lambda\right\rangle_\beta$. |
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