Dimensions on Lattice Ordered Abelian Groups and Model Theory of Modules over Pr\"ufer Domains

Abstract

We prove a transfer theorem which, when combined with the Jaffard-Kaplansky-Ohm Theorem, allows results in model theory of modules over B\'ezout domains to be translated into results over Pr\"ufer domains via their value groups. Extending work of Puninski and Toffalori, we show that the extended positive cone of the value group of a Pr\"ufer domain has m-dimension if and only if its lattice of pp-$1$-formulae has breadth (equivalently width) and that these dimensions are equal. Further, we show that the existence of these dimensions is equivalent to the lattice of pp-$1$-formulae having m-dimension (and hence to its Ziegler spectrum having Cantor-Bendixson rank) and the non-existence of superdecomposable pure-injective modules. Finally, we give a best possible upper bound for the m-dimension of the pp-$1$-lattice of a Pr\"ufer domain in terms of the m-dimension of the extended positive cone of its value group and show that all ordinals which are not of the form $\lambda+1$ for $\lambda$ a limit ordinal occur as the m-dimension of the pp-$1$-lattice of a B\'ezout domain.