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 |
|---|---|
| Pages (from-to) | 307-314 |
| Number of pages | 8 |
| Journal | Notre Dame Journal of Formal Logic |
| Volume | 52 |
| Issue number | 3 |
| DOIs | |
| State | Published - 19 Aug 2011 |
Keywords
- Boolean algebras
- Constructability
- Depth
All Science Journal Classification (ASJC) codes
- Logic