Good and bad points in scales

Chris Lambie-Hanson
2014 Archive for Mathematical Logic  
We address three questions raised by Cummings and Foreman regarding a model of Gitik and Sharon. We first analyze the PCF-theoretic structure of the Gitik-Sharon model, determining the extent of good and bad scales. We then classify the bad points of the bad scales existing in both the Gitik-Sharon model and other models containing bad scales. Finally, we investigate the ideal of subsets of singular cardinals of countable cofinality carrying good scales.
doi:10.1007/s00153-014-0387-6 fatcat:ba2csq7usbcbdomjxsivms22by