Groups Acting on Trees

Groups are one of the most fundamental algebraic concepts in mathematics, and they can be studied through their actions on other objects. Special attention of geometic group theorists has been given to the actions on trees. This paper explores consequences that can be derived from groups acting on those spaces. We discuss and present the theory of R-trees, and Bass–Serre theory, as well as complexes of groups. We discuss applications of R-trees, ends of groups and apply some of the theory to the class of Baumslag-Solitar
groups.