Abstract
Suppose D is an ultrafilter on κ and λκ = λ. We prove that if Bi is a Boolean algebra for every i < κ and λ bounds the depth of every Bi , then the depth of the ultraproduct of the Bi 's mod D is bounded by λ+. We also show that for singular cardinals with small cofinality, there is no gap at all. This gives a partial answer to a previous problem raised by Monk.
Original language | English |
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Pages (from-to) | 307-314 |
Number of pages | 8 |
Journal | Notre Dame Journal of Formal Logic |
Volume | 52 |
Issue number | 3 |
DOIs | |
State | Published - 2011 |
Keywords
- Boolean algebras
- Constructability
- Depth