Ulrich modules over cyclic quotient surface singularities

In this paper, we characterize Ulrich modules over cyclic quotient surface singularities using the notion of special Cohen-Macaulay modules. We also investigate the number of indecomposable Ulrich modules for a given cyclic quotient surface singularity, and show that the number of exceptional curves in the minimal resolution determines a boundary on the number of indecomposable Ulrich modules.