# Wolfgang Alt

### Quick Info

Hilden, Mettmann, Germany

**Wolfgang Alt**is a German mathematical biologist who has made highly significant contributions to revolutionising the topic. He led the "Theoretical Biology" department at the University of Bonn for many years.

### Biography

**Wolfgang Alt**was the son of Willy Alt (1909-1997) and Auguste Leonie Ingenerf (1918-2006) known as 'Leonie'. Willy Alt, son of Wilhelm Alt (1884-1982) and Elisabetha Weissmann (1885-1969), born 27 August 1909 in Heltersberg, Germany, had entered the University of Würzburg in 1931. There he studied mathematics, physics and astronomy and was awarded a doctorate in 1937. From 1946 he worked at the Leibniz Gymnasium in Düsseldorf. He married Auguste Leonie Ingenerf on 25 August 1944 in Hilden, Mettmann. Leonie Ingenerf was the daughter of a confectionery wholesaler who had moved to Hilden in 1907 as a sales assistant, bought a house there and opened a café. Leonie was born in that house on 15 October 1918 and by the time of her marriage was working as a chemical laboratory assistant. From 1958 Willy Alt taught at the Schloss Gymnasium in Benrath, close to Hilden, where he set up a school observatory. He retired as a teacher in 1974 but continued as head of the observatory until 1979.

Willy and Leonie Alt had two sons: Hans Wilhelm Alt was born in 1945 and Wolfgang Alt, the subject of this biography, was born in 1947. Before continuing with Wolfgang Alt's biography, let us give some details of his older brother Hans Wilhelm Alt since he also became a mathematician. Hans Wilhelm attended the Helmholtz-Gymnasium in Hilden and was awarded his Abitur in 1965. He then studied mathematics at the University of Göttingen and undertook research for his doctorate advised by Erhard Heinz (1924-2017). He was awarded his doctorate in 1971 for his thesis

*Verzweigungspunkte von H-Flächen*Ⓣ. He became a Professor of Applied Mathematics at the Institute for Applied Mathematics at the University of Bonn. He retired in 2010 and in the following year was made an honorary professor at the Technical University of Munich. Some of his major contributions are given in [14]:-

He managed to solve problems with so-called free margins. Such mathematical modelling describes, for example, the interface between different phases of a liquid, whose shape and position and possibly even their presence are initially unknown. He wrote a number of important contributions to the variational theory of elliptic and parabolic free boundary value problems. In particular, the publication on nonlinear parabolic equations written together with Stephan Luckhaus and the ground-breaking work on the beam problem received worldwide attention.Wolfgang Alt was a couple of years younger than his brother and, influenced by him, followed a similar school and university career. Like his brother, he attended the Helmholtz-Gymnasium in Hilden. This school, founded in 1910, was named after Hermann von Helmholtz and originally specialised in mathematics and science. From 1923 the school became an Oberrealschule and students could take the general university entrance qualification. Alt graduated from the school in 1966 and, again like his brother, studied mathematics at the Georg-August University of Göttingen. He graduated from the University of Göttingen in 1971 with a Diploma in Mathematics and then went to the University of Münster to study for his doctorate.

At the University of Münster, Alt's thesis advisor was Willi Jäger. Jäger, who was born on 15 August 1940 in Kschellowitz, Bohemia, had studied for his doctorate at the Ludwig-Maximilians University of Munich advised by Erhard Heinz. Let us note that Wolfgang Alt's older brother Hans Wilhelm Alt had also had Erhard Heinz as his thesis advisor. Jäger had been awarded his doctorate in 1966 for his thesis

*Über das Dirichlet-Problem in Außengebieten für die Schwingungsgleichung*Ⓣ and, after spending a year at the Courant Institute in New York City, had been appointed as a professor of mathematics at the University of Münster in 1970.

Hans Engler describes meeting Wolfgang Alt in 1971 not long after he began his doctoral studies in Münster [6]:-

Wolfgang and I met on 12 October 1971 shortly after 11:15 in the morning in the M1 lecture hall at the University of Münster. Or rather, around 400 freshmen in the Calculus I class got to know Wolfgang, and I was among them. Wolfgang and his brother Hans Wilhelm were the assistants who supervised this lecture for Willi Jäger. In this beginner's lecture, metric spaces were introduced before real numbers, or perhaps a week later. Wolfgang and Hans Wilhelm introduced us to these abstract concepts using all possible means, for example by decorating exercise sheets and scripts with the adventures of mathematically inspired stick figures.Wolfgang Alt received his doctorate from the University of Münster in 1973 for his thesis

*Regularitätssätze für singuläre Integrale mit gemischten Homogenitäten und ihre Anwendung auf Integraldarstellungen in der komplexen Funktionentheorie mehrerer Variabler*Ⓣ on the functions of several complex variables. Alt published two papers related to his thesis, both appearing in 1974, namely:

*Singuläre Integrale mit gemischten Homogenitäten auf Mannigfaltigkeiten und Anwendungen in der Funktionentheorie*Ⓣ and

*Hölderabschätzungen für Ableitungen von Lösungen der Gleichung $\bar\partial u = f$ bei streng pseudokonvexem Rand*Ⓣ. In the first of these he gives the acknowledgement:-

I would especially like to thank Prof W Jäger and Prof N Kerzman for their suggestions.We note that Norberto Kerzman (1943-2019) was born in Buenos Aires, Argentina, obtained his Ph.D. from New York University in 1970 and then began his career at Princeton and MIT. The second of Alt's papers has the acknowledgement:-

I would especially like to thank Prof Jäger and Prof Lieb for suggestions and advice in completing my dissertation, the second part of which resulted in this work.We note that Ingo Lieb (born 4 September 1939 in Hanover) studied physics and mathematics at the University of Göttingen. He was advised by Hans Grauert and awarded his doctorate in 1965. After being an assistant at Göttingen from 1965 to 1971, during which time he got to know Wolfgang Alt, he spent 1971-72 at Princeton before being appointed as a professor at the University of Münster.

Hans Engler writes [6]:-

I began my thesis in the fall of 1974, and Wolfgang was my immediate supervisor. The support was very good - he suggested directions that were promising, warned against other directions that promised difficulties or little success, and gave me a lot of leeway. Maybe too much, the work ended up being quite long.Willi Jäger became professor of applied mathematics at the Heidelberg University in 1974. Alt became an assistant at Heidelberg University. Hans Engler writes [6]:-

From the spring of 1975, most of the members (assistants, doctoral students, many graduate students) of the Jäger working group moved to Heidelberg. We all spent a lot more time together than before in Münster. Hikes in the Odenwald and bike tours in the Palatinate wine regions, football games on a meadow near the institute, seminar weeks in the Black Forest at the Fehrenbacher Hof and in the Vosges, trips together to conferences, and I have very fond memories of an election party in 1976 at the house of Wolfgang and his then wife Inge on Monchhofstrasse (when Helmut Schmidt was re-elected).Alt began to move towards applied mathematics topics and his next two publications were on periodicity. The first was

*Some periodicity criteria for functional differential equations*(1978) which has the following Abstract:-

Using the classical fixed point index for cones in a Banach space some criteria for the existence of periodic solutions of autonomous functional differential equations $\dot{x}(t) = F(x_t)$ are derived, regarding the asymptotic behaviour of F near zero and infinity. The general result is applied to equations with distributed time delay.He extended this work in the paper

*Periodic solutions of some autonomous differential equations with variable time delay*which was published in the

*Proceedings*of the Summer School on 'Functional differential equations and approximation of fixed points' held at the University of Bonn in July 1978.

This work on periodicity was only a diversion from the main direction that his interests were going, for, beginning in 1975, he was involved with studying cell biology at the Deutsches Krebsforschungszentrum, the German Cancer Research Centre, in Heidelberg. This Research Centre had been founded in 1964 and became a member of the Association of National Research Centres in 1975. Alt worked on a biased random walk models for chemotaxis and was awarded his habilitation from the University of Heidelberg in 1980 having submitted the thesis

*Vergleichsätze für quasilineare elliptisch-parabolische Systeme partieller Differentialgleichungen*Ⓣ. Hans Engler writes [6]:-

I had proofread his habilitation thesis from this time, in which his theory on biased random walk models for chemotaxis was developed in detail, and I clearly remember the impression that I had never seen anything like it before: something new under the sun.In 1978, Alt became a co-founder of SFB 123 "Stochastic, Mathematical Models" at the University of Heidelberg which was set up with Willi Jäger as its chairman. A conference on 'Models of Biological Growth and Spread', was held at the German Cancer Research Centre in Heidelberg and at the Institute of Applied Mathematics of the University of Heidelberg, 16-21 July 1979. The Proceeding [9] were published in 1980:-

The main theme of the conference was the mathematical representation of biological populations with an underlying spatial structure. An important feature of such populations is that they and/or their individual components may interact with each other. Such interactions may be due to external disturbances, internal regulatory factors or a combination of both. Many biological phenomena and processes including embryogenesis, cell growth, chemotaxis, cell adhesion, carcinogenesis, and the spread of an epidemic or of an advantageous gene can be studied in this context. Thus, problems of particular importance in medicine (human and veterinary), agriculture, ecology, etc. may be taken into consideration and a deeper insight gained by utilising (more) realistic mathematical models. Since the intrinsic biological mechanisms may differ considerably from each other, a great variety of mathematical approaches, theories and techniques is required. The aims of the conference were (i) To provide an overview of the most important biological aspects. (ii) To survey and analyse possible stochastic and deterministic approaches. (iii) To encourage new research by bringing together mathematicians interested in problems of a biological nature and scientists actively engaged in developing mathematical models in biology.Alt played a large role in organising the conference and his paper

*Biased random walk models for chemotaxis and related diffusion approximations*, closely related to his habilitation, was published in the

*Proceedings*in 1980. This paper has the Abstract:-

Stochastic models of biased random walk are discussed, which describe the behaviour of chemosensitive cells like bacteria or leukocytes in the gradient of a chemotactic factor. In particular the turning frequency and turn angle distributions are derived from certain biological hypotheses on the background of related experimental observations. Under suitable assumptions it is shown that solutions of the underlying differential-integral equation approximately satisfy the well-known Patlak-Keller-Segel diffusion equation, whose coefficients can be expressed in terms of the microscopic parameters. By an appropriate energy functional a precise error estimation of the diffusion approximation is given within the framework of singular perturbation theory.Alt spent the year 1982-83 in the United States as a visiting associate professor at the University of Utah in Salt Lake City. The American Mathematical Society held its 804th meeting at the University of Utah in Salt Lake City 29-30 April 1983. A Special Session was held on

*Nonlinear elliptic and parabolic partial differential equations*and Alt was invited to lecture at this session.

In 1986 Alt was appointed as a professor at the University of Bonn and became the founder and head of the "Theoretical Biology" department in the Faculty of Mathematics and Natural Sciences at the University of Bonn. Diedrik Menzel addresses Alt as he writes in [12]:-

Because of the interdisciplinary nature of your field of work, you could just as easily have been based at the Zoological Institute when you were appointed to Bonn in 1986. We are glad that this did not happen then. We owe it to this fortunate circumstance that you have stood by us as a reliable and lovable colleague in all matters relating to the Institute over the many years.Heike Lischke was a diploma student at Bonn when Alt arrived. She tells us in [11] about her first interactions with Alt:-

A new professor had recently moved into our rooms down on Kirschallee. We were a small group of biology graduate students and doctoral students of other professors who were struggling with all sorts of biological modelling. ... In my diploma thesis, I had been trying for some time to get my model to reproduce the plankton data in the Haltern reservoir, with moderate success. At first we were a bit sceptical about the new "office roommate", after all the new professor belonged to the exotic species of "mathematician". But we quickly realised that he didn't fit our stereotype of the distinguished professor or unworldly mathematician; he was friendly, and rather hip and alternative. Some of his hallmarks were colourful scarves and constant consumption of carrots.Vincenzo Capasso writes in [5] about Alt:-

My first contact with him made me I wanted to sink into the ground. He happened to be passing by the copier just as I was trying to secretly scrape the smudged film off the rollers, which had stuck there due to my improper handling. Instead of continuing without comment, he offered to help me too!

A few days later I wanted to make a pot of tea for all of us. The kettle that we used for our immense tea consumption was in his office. I noticed he wasn't there right then. So I turned on the stove, emptied the tea strainer with the old, dried-out tea, and briefly went back to my terminal. Shortly afterwards, a rather irritated Wolfgang stood in our room and asked: "Do any of you know where my special (XY) tea blend has gone? I was just about to make myself a nice cup and had already filled the tea strainer?" My second sinking into the ground ...

What is astonishing is that despite this somewhat unfortunate start, Wolfgang then set the course for my career, as he found me the doctoral position in Heidelberg (of all things in mathematics), supervised my dissertation from a distance, and also had a hand in arranging a postdoc position for me in Zurich.

What I have always liked a lot of Wolfgang, has been his genuine interest for biology, though with a deep competence in advanced methods of mathematics. Different from many biomathematicians, he has always been method independent, since at the centre of his scientific concern has been the biological problems.Let us give another tribute, this time from Michael Welter [15]:-

His communication skills being excellent, once, for a lecture of his on chemotaxis, he impressed me and the whole audience by carrying in the lecture hall a basin with two real insects swimming in water that he had just taken from a pond!

He has been always a source of enthusiasm for science at large, with a spirit of curiosity that many time professional academicians loose too early, moved by career and competition to fast publishing of about anything.

...

I like to mention that we also share a great interest in supporting young scientists; Wolfgang is very special as a teacher putting himself all the time aside if required, to emphasise the importance of the contribution by the young members of his team.

The University of Bonn is very lucky to have him among its faculty members, and all of us are grateful to Wolfgang for his strong and enthusiastic support to the interdisciplinary field of mathematical and theoretical biology.

Working with you is always a pleasure; regardless of whether it is about the mathematics education of biology students or the history of the university.Wolfgang Alt is a member of the Society for Mathematical Biology, of the German Society for the History and Theory of Biology, and of the German Mathematical Society. He has served as president of the European Society for Mathematical and Theoretical Biology.

When I gave the mathematics lecture "Mathematics in Biology" for the first time in the winter semester of 2006/07, you made it incredibly easy for me to get started. Your concept, which includes the interlinking of theoretical knowledge in mathematics and biology with applied project work, including on computers in small groups, was convincing from the start and has survived the not insignificant changes, which brought with it the change to the bachelor's and master's degree programmes.

In March 1989, the workshop 'Biological motion' was held in Königswinter, Germany and theProceedingswere published in 1990 with Wolfgang Alt and Gerhard Hoffmann as editors. The editors wrote the Preface and we give an extract (see [17]):-

During the 70's, when Biomathematics (beyond Biomedical Statistics and Computing) became more popular at universities and research institutes, the problems dealt with came mainly from the general fields of 'Population Biology' and 'Complex Systems Analysis' such as epidemics, ecosystems analysis, morphogenesis, genetics, immunology and neurology. Since then, the picture has not considerably changed, and it seems that "a thorough analysis of behaviour" of single organisms and, moreover, of their mutual interactions, is far from being understood. On the contrary, mathematical modellers and analysts have been well-advised to restrict their investigations to specific aspects of 'biological behaviour', one of which is 'biological motion'.

...

The idea for this Workshop, the Proceedings of which we now present, arose between 1987 and 1988, when Gerhard Hoffmann from Würzburg and Hans Scharstein from Koln had reported on their work on Animal Physiology at the Biomathematical Colloquium organised by three colleagues in Bonn. In response, one of these, Wolfgang Alt, visited the Zoological Institute at Köln (group of Gernot Wendler) and was fascinated by a colloquium talk on ciliary motion presented by Hans Machemer from the Cell Physiology Department in Bochum, in particular by the demonstration of his famous plastic flagella model. Finally, coming into mind as participant of an interesting meeting on chemotaxis of leukocytes, Hans Gruler from the Biophysics Department in Ulm joint us and completed the group of five organisers. We soon developed the concept of a four-day Workshop on "Modelling, Analysis and Simulation of Biological Motion" and requested various scientists to assemble for a discussion of our main topic: "Mechanisms and Control of Locomotion". The selection of motile species taken into consideration was clearly influenced by the organisers' own research fields: predominantly unicellular organisms, blood and tissue cells, but also insects, crustaceans and even fish were placed 'on the table'.

... the atmosphere during the Workshop was exciting, and it stimulated a continuous work from Thursday evening, 16 March, until Sunday morning, 19 March, 1989, in the comfortable 'Stegerwaldhaus' of the Jakob-Kaiser-Stiftung placed at the little wine-growing village Königswinter on the Rhine, opposite to Bonn and at the foot of the 'Drachenfels'. Those who never can finish a discussion concluded the Workshop by a walk through the forest around this pleasant hill.

...

... the complex dynamical systems inducing the 'miracles' of naturally evolved 'biological motors' (on the individual side) and resulting cooperative movements of organisms (on the population side) require adequate mathematical theories and techniques to give insight into the underlying highly non-linear world of spatio-temporal phenomena. Therefore, it has been very fortunate for the Workshop to obtain generous financial, material and personnel support by the Research Program SFB 256 on "Non-linear Partial Differential Equations" sponsored by the German Research Fond (DFG).

Alt has local history as a hobby and is a member of the Poppelsdorf History Association. We note that Poppelsdorf is a district of Bonn which contains the science departments of the University of Bonn. He has co-authored several books on the history of Poppelsdorf, including

*Spurensuche in Poppelsdorf: die kurfürstliche Zeit; ein Führer zu kulturhistorischen Rundgängen*Ⓣ (2002), and

*Kirmes-Rausch in Poppelsdorf: Kulturgeschichte eines Bonner Volksfestes: Dokumente - Erinnerungen - Analysen - Deutungen*Ⓣ (2021).

Let us end this biography was this tribute from Philip Maini [18]:-

The work that you and the Theoretical Biology group at Bonn have done has been outstanding and an inspiration to all of us in mathematical biology. It has always been exciting to visit Bonn and to talk with the group there and at conferences and meetings. In particular, talking with you about science or other things is always a pleasure.

### References (show)

- M Bock and M P Knappitsch (eds.),
*European Communications in Mathematical and Theoretical Biology***14**(2011), 1-57. - M Bock and M P Knappitsch, Editorial,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 1-2. - C A Braumann, Dear Wolfgang - Greetings,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 3. - T Bretschneider, Dear Wolfgang - Greetings,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 3-4. - V Capasso, Dear Wolfgang - Greetings,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 4-5. - H Engler, Wolfgang- Grussworte,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 5-6. - M Griebel, Lieber Wolfgang - Grussworte,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 6-7. - V Herzog and G Kirfel, 22 Jahre wissenschaftlicher Austausch zwischen Zellbiologie und Theoretischer Biologie,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 30-31. - W Jäger, H Rost and P Tautu (eds.), Biological Growth and Spread, Mathematical Theories and Applications, Proceedings of a Conference Held at Heidelberg, 16 -21 July 1979 (Springer, 1980).
- M P Knappitsch and G C Bukow, Ein interdisziplinärer Brückenschlag: Arbeitskreis Wissenschaftstheorie der Biologie und Bionik,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 33-40. - H Lischke, Der neue Prof,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 13. - D Menzel, Lieber Wolfgang,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 9. - C Möhl, Wandernde Zellen - Als Diplomand in der Theoretischen Biologie,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 31-33. - Prof Dr Hans Wilhelm Alt wird Honorarprofessor an der TUM,
*Technical University of Munich*(23 September 2011).

https://portal.mytum.de/pressestelle/meldungen/NewsArticle_20110923_105215 - M Welter, Lieber Wolfgang,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 10. - Wolfgang Alt,
*Mathematics Genealogy Project*.

https://www.mathgenealogy.org/id.php?id=37263 - W Alt and G Hoffmann (eds.),
*Biological motion*(Springer-Verlag, Berlin, 1989). - P Maini, Dear Wolfgang,
*European Communications in Mathematical and Theoretical Biology***14**(2011), 9.

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Written by J J O'Connor and E F Robertson

Last Update June 2024

Last Update June 2024