# Dietrich Stoyan

Dietrich Stoyan (born November 26, 1940, Berlin) is a German mathematician and statistician who made contributions to queueing theory, stochastic geometry, and spatial statistics.

## Education and career

Stoyan studied mathematics at Technical University Dresden; applied research at Deutsches Brennstoffinstitut Freiberg, 1967 PhD, 1975 Habilitation. Since 1976 at TU Bergakademie Freiberg, Rektor of that university in 1991—1997. He became famous by his statistical research of the diffusion of euro coins in Germany and Europe after the introduction of the euro in 2002. In 2024, he criticized together with Sung Nok Chiu a wrong proof of the hypothesis that the origin of the COVID-19 pandemic was a market in Wuhan, which was published in the journal Science.
Dietrich Stoyan is an honorary doctor of the Technical University of Dresden (2000) and the University of Jyväskylä (2004). He was a member of the Academy of Sciences of the GDR (1990), which disappeared in 1991. At present he is a member of the Academia Europaea (since 1992), the Berlin-Brandenburg Academy of Sciences (since 2000) and the German Academy of Sciences Leopoldina (since 2002). He is also a Fellow of the Institute for Mathematical Statistics (since 1997). In 2018 he published his autobiography In two times.

## Research
### Queueing Theory

Qualitative theory, in particular inequalities, for queueing systems and related stochastic models. The books
* D. Stoyan: Comparison Methods for Queues and other Stochastic Models. J. Wiley and Sons, Chichester, 1983 and
* A. Mueller and D. Stoyan: Comparison Methods for Stochastic Models and Risks, J. Wiley and Sons, Chichester, 2002
report on the results. The work goes back to 1969 when he discovered the monotonicity of the GI/G/1 waiting times with respect to the convex order.

### Stochastic Geometry

Stereological formulae, applications for marked point processes, development of stochastic models. Successful joint work with Joseph Mecke led to the first exact proof of the fundamental stereological formulae.
A book entitled "Stochastic Geometry and its Applications" reports on these results. Its 3rd edition is the key reference for applied stochastic geometry.

### Spatial Statistics

Statistical methods for point processes, random sets and many other random geometrical structures such as fibre processes. Results can be found in the 2013 book on stochastic geometry and in the book, Fractals, Random Shapes and Point Fields by D. and H. Stoyan. (J. Wiley and Sons, Chichester, 1994).
A particular strength of Stoyan is second-order methods.
He is also the main author of the book Statistical analysis and modelling of spatial point patterns. It treats the statistics of point patterns with methods of point process theory.
Stoyan is very active in demonstrating non-mathematicians and non-statisticians the potential of statistical and stochastic geometrical methods. He published many papers in journals of physics, materials science, forestry, and geology. One topic of particular interest was random packings of hard spheres. He co-organized together with Klaus Mecke conferences where physicists, geometers and statisticians met. See the books
* Mecke Klaus R. and Stoyan D. (eds.): Statistical Physics and Spatial Statistics. Lecture Notes in Physics 554, Springer-Verlag, 2000 and
* Mecke Klaus R. and Stoyan D. (eds.): Morphology of Condensed Matter. Lecture Notes in Physics 600, Springer-Verlag, 2002.