Grassberger's early work focused on particle phenomenology, in particular on the formulation of formally exact equations for three-body scattering and bound state scattering (Alt-Grassberger-Sandhas equation). While working at
CERN, he realized that reggeon field theory can be viewed as a
contact process in the same
universality class as
directed percolation. After making this discovery, Grassberger turned his attention to the studies of
statistical physics,
dynamical systems, sequential sampling algorithms, and
complex systems. His publications span a variety of topics including
reaction-diffusion systems,
cellular automata,
fractals,
Ising model, Griffiths phases,
self-organized criticality, and
percolation. He held long-term positions at the
University of Wuppertal and at the
Forschungszentrum Jülich (Germany). Other positions that lasted between 2 years and 3 months were at
CERN, at the Universities of Kabul, Nice, Calgary, Rome and Utrecht, the
Weizmann Institute, the
Max Planck Institute for the Physics of Complex Systems in Dresden, the in Florence, and at the
Institute for Advanced Studies in Basic Sciences in Zanjan, Iran. In 2017 he received the
EPS Statistical and Nonlinear Physics Prize. ==See also==