Speaker: Mohammad Moghaddam (IPM, Teheran, Iran) Title: The topological, metric and parametric structures on the space of valuations centered on a ring Abstract: In algebraic geometry, the topological study of the space of valuations, Riemann-Zariski manifold, began by the work of Zariski on local uniformization problem. We show that the structure of this space can be studied be the use of two different representations of the valuations, i.e., the key-polynomial and the generalized power series representation of the valuations. These different descriptions allows us to study the contact structure of the valuations on the Riemann-Zariski manifold and to interpret the contact in terms of the truncations of generalized power series. Moreover, it allows us to give a natural parametrization of the Riemann-Zariski manifold.