ar X iv : n uc l - th / 9 90 30 59 v 1 2 5 M ar 1 99 9 Testing the Space - Time Structure of Event Generators In memory of Klaus Kinder - Geiger

Combined presentation of the talks given by the two authors at the workshop " RHIC Physics and Beyond – Abstract. We report on work done in collaboration with Klaus Kinder-Geiger and John Ellis which aims at connecting the space-time structure of event generator simulations with observable output. Klaus Geiger was an important driving force in our search for understanding the dynamics of ultrarelativistic heavy-ion collisions and quark-gluon plasma. An unconventional and unique character – this is how we will remember him. Physics was his passion, but he also loved his Porsche and his MG (= " Ma Geiger "). It is hard for us to accept that by his untimely death Klaus, whose research was dedicated so much to the future, in particular to the RHIC program at Brookhaven, should be imprisoned forever in the past. As his friends and collaborators, we will try to carry on his legacy. The main focus of Klaus' work during the last years of his life was the event generator VNI which describes relativistic heavy-ion collisions and high energy particle collisions in terms of a perturbative parton shower Monte Carlo in phase-space combined with a simple space-time hadronization prescription. A partonic starting point is certainly required at ultrarelativistic collision energies, √ s > ∼ 100 A GeV, where perturbative contributions start to account for a significant part of the measured particle production. With his Parton Cascade Model [1], later amended