Title: Delta invariant formulae of curves on rational surface singularities

Abstract: The aim of this talk is to show that the delta invariant of a
complex curve germ is the periodic constant of  the Campillo, Delgado and
Gusein-Zade?s Poincaré series associated with the curve. This can be used to
prove simple formulae for the delta invariant in the case when the curve is
embedded in a rational surface singularity. Joint work  with J.I.
Cogolludo-Agustín, J. Martín-Morales and A. Némethi.