Sandwiching the Consistency Strength of Two Global Choiceless Cardinal Patterns

• Autorzy: Arthur W. Apter
• Języki publikacji: EN

Abstrakty

EN

We provide upper and lower bounds in consistency strength for the theories "ZF + $¬AC_ω$ + All successor cardinals except successors of uncountable limit cardinals are regular + Every uncountable limit cardinal is singular + The successor of every uncountable limit cardinal is singular of cofinality ω" and "ZF + $¬AC_ω$ + All successor cardinals except successors of uncountable limit cardinals are regular + Every uncountable limit cardinal is singular + The successor of every uncountable limit cardinal is singular of cofinality ω₁". In particular, our models for both of these theories satisfy "ZF + $¬AC_ω$ + κ is singular iff κ is either an uncountable limit cardinal or the successor of an uncountable limit cardinal".

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Bulletin of the Polish Academy of Sciences. Mathematics
• Rocznik: 2009
• Tom: 57
• Numer: 3
• Strony: 189-197

Daty

wydano

2009

Twórcy

autor

Arthur W. Apter

• Department of Mathematics, Baruch College of CUNY, New York, NY 10010, U.S.A.
• The CUNY Graduate Center, Mathematics, 365 Fifth Avenue, New York, NY 10016, U.S.A.

Identyfikatory

DOI

10.4064/ba57-3-1