On the order dimension of locally countable partial orderings

Autor: Higuchi, Kojiro, Lempp, Steffen, Raghavan, Diip, Stephan, Frank
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
Popis: We show that the order dimension of the partial order of all finite subsets of $\kappa$ under set inclusion is ${\log}_{2}({\log}_{2}(\kappa))$ whenever $\kappa$ is an infinite cardinal. We also show that the order dimension of any locally countable partial ordering $(P, <)$ of size $\kappa^+$, for any $\kappa$ of uncountable cofinality, is at most $\kappa$. In particular, this implies that it is consistent with ZFC that the dimension of the Turing degrees under partial ordering can be strictly less than the continuum.
Databáze: arXiv