Automorphisms of locally string algebras

It is known that automorphisms of finite-dimensional bound quiver algebras decompose into inner automorphisms and automorphisms which permute the vertices. In this paper, we show that for string algebras, automorphisms permuting vertices further decompose into a graded automorphism and a composition of certain types of exponential automorphisms. Moreover, the same decomposition applies to automorphisms of locally string algebras, which are an analogue of string algebras wherein the finite-dimensional condition is omitted.