Universidad Nacional Autónoma de México. Centro de Ciencias Matemáticas Journal of Logic and Analysis; http://logicandanalysis.org/index.php/jla/article/view/285
Resumen
In this work we study cardinal invariants of the ideal SP of strongly porous sets on ω2. We prove that add(SP) = ω1 , cof(SP) = c and that it is consistent that non(SP) < add(N ), answering questions of Hrušák and Zindulka. We also find a connection between strongly porous sets on ω2 and the Martin number for σ-linked partial orders, and we use this connection to construct a model where all the Martin numbers for σ-k-linked forcings are mutually different.
O. Guzmán, M. Hrusak and A. Martínez, Cardinal invariants of strongly porous sets, Journal of Logic Analysis, vol. 9, (2017), no. 6, 1-16, https://repositorioccm.matmor.unam.mx/handle/123456789/161
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El uso de este contenido digital se rige por una licencia Creative Commons BY 3.0 Internacional, https://creativecommons.org/licenses/by/3.0/legalcode.en/, fecha de asignación de la licencia 2017-12.