Two Remarks on First-Order Theories of Baumslag-Solitar Groups
arXiv:1002.2658
Abstract
In this note we characterise all finitely generated groups elementarily equivalent to a solvable Baumslag-Solitar group BS. It turns out that a finitely generated group is elementarily equivalent to BS if and only if is isomorphic to BS. Furthermore, we show that two Baumslag-Solitar groups are existentially (universally) equivalent if and only if they are elementarily equivalent if and only if they are isomorphic.
arXiv comment5 pages, no figures. Version 3 corrects a mistake pointed out to us by G. Levitt