Peter Grassberger (born 17 May 1940) is a retired professor who worked in statistical and

particle physics Particle physics or high-energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the s ...

. He made contributions to

chaos theory Chaos theory is an interdisciplinary area of Scientific method, scientific study and branch of mathematics. It focuses on underlying patterns and Deterministic system, deterministic Scientific law, laws of dynamical systems that are highly sens ...

, where he introduced the idea of

correlation dimension In chaos theory, the correlation dimension (denoted by ''ν'') is a measure of the dimensionality of the space occupied by a set of random points, often referred to as a type of fractal dimension. For example, if we have a set of random points on t ...

, a means of measuring a type of

fractal dimension In mathematics, a fractal dimension is a term invoked in the science of geometry to provide a rational statistical index of complexity detail in a pattern. A fractal pattern changes with the Scaling (geometry), scale at which it is measured. It ...

of the

strange attractor In the mathematics, mathematical field of dynamical systems, an attractor is a set of states toward which a system tends to evolve, for a wide variety of starting conditions of the system. System values that get close enough to the attractor va ...

Work

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 The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in Meyrin, western suburb of Gene ...

, he realized that reggeon field theory can be viewed as a

contact process The contact process is a method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, because it is susceptible to reacting with arsenic impu ...

in the same

universality class In statistical mechanics, a universality class is a collection of mathematical models which share a single scale-invariant limit under the process of renormalization group flow. While the models within a class may differ dramatically at finite sc ...

directed percolation In statistical physics, directed percolation (DP) refers to a class of models that mimic filtering of fluids through porous materials along a given direction, due to the effect of gravity. Varying the microscopic connectivity of the pores, these ...

. After making this discovery, Grassberger turned his attention to the studies of

statistical physics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. Sometimes called statistical physics or statistical thermodynamics, its applicati ...

dynamical systems In mathematics, a dynamical system is a system in which a Function (mathematics), function describes the time dependence of a Point (geometry), point in an ambient space, such as in a parametric curve. Examples include the mathematical models ...

, sequential sampling algorithms, and

complex systems A complex system is a system composed of many components that may interact with one another. Examples of complex systems are Earth's global climate, organisms, the human brain, infrastructure such as power grid, transportation or communication s ...

. His publications span a variety of topics including reaction-diffusion systems,

cellular automata A cellular automaton (pl. cellular automata, abbrev. CA) is a discrete model of computation studied in automata theory. Cellular automata are also called cellular spaces, tessellation automata, homogeneous structures, cellular structures, tessel ...

fractals In mathematics, a fractal is a Shape, geometric shape containing detailed structure at arbitrarily small scales, usually having a fractal dimension strictly exceeding the topological dimension. Many fractals appear similar at various scale ...

Ising model The Ising model (or Lenz–Ising model), named after the physicists Ernst Ising and Wilhelm Lenz, is a mathematical models in physics, mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables that r ...

, Griffiths phases,

self-organized criticality Self-organized criticality (SOC) is a property of dynamical systems that have a critical point as an attractor. Their macroscopic behavior thus displays the spatial or temporal scale-invariance characteristic of the critical point of a phas ...

, and

percolation In physics, chemistry, and materials science, percolation () refers to the movement and filtration, filtering of fluids through porous materials. It is described by Darcy's law. Broader applications have since been developed that cover connecti ...

. He held long-term positions at the

University of Wuppertal The University of Wuppertal (''Universität Wuppertal'') is a German scientific institution located in Wuppertal in the state of North Rhine-Westphalia, Germany. The university's official name in German is ''Bergische Universität Wuppertal'' ...

and at the

Forschungszentrum Jülich Forschungszentrum Jülich (FZJ; “Jülich Research Centre”) is a German national research institution that pursues interdisciplinary research in the fields of energy, information, and bioeconomy. It operates a broad range of research infrast ...

(Germany). Other positions that lasted between 2 years and 3 months were at

, at the Universities of Kabul, Nice, Calgary, Rome and Utrecht, the

Weizmann Institute The Weizmann Institute of Science ( ''Machon Weizmann LeMada'') is a Public university, public research university in Rehovot, Israel, established in 1934, fourteen years before the State of Israel was founded. Unlike other List of Israeli uni ...

, the

Max Planck Institute for the Physics of Complex Systems The Max Planck Institute for the Physics of Complex systems is one of the 80 institutes of the Max-Planck-Gesellschaft, located in Dresden, Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. I ...

in Dresden, the in Florence, and at the

Institute for Advanced Studies in Basic Sciences An institute is an organizational body created for a certain purpose. They are often research organisations (research institutes) created to do research on specific topics, or can also be a professional body. In some countries, institutes ca ...

in Zanjan, Iran. In 2017 he received the

EPS Statistical and Nonlinear Physics Prize The EPS Statistical and Nonlinear Physics Prize is a biannual award by the European Physical Society (EPS) given since 2017. Its aim is to recognize outstanding research contributions in the area of statistical physics, nonlinear physics, comple ...

Selected publications

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References

Austrian physicists People associated with CERN Academic staff of the University of Calgary Living people 1940 births {{physicist-stub

Work

See also

Selected publications

References