An interview with Karl-Theodor Sturm, coordinator and speaker of the Hausdorff Center for Mathematics

held by Stefan Hartmann, Scientific Associate at HCM (PR and Events) 


By now, the Hausdorff Center in Bonn is not the only mathematical Cluster of Excellence anymore - there are three more in Berlin, Münster and Heidelberg. What does that mean for Bonn - and for Germany?

Sturm: The decision of the excellence commission was excellent news. The more mathematics gets supported, the more it not only benefits the subject itself but also Germany as a place for technology and science. The other clusters add to our profile in a complementary way. Without trying to diminish national competition within Germany: We rather see our competitors in the international market. The globalization and increasing mobility of our researchers are undeniable facts - and independent of the discipline, Germany still does not rank among the best locations for science in this development. We, the Hausdorff Center for Mathematics, are determined to take up the challenges that come with globalization and to take advantage of these.

What is Bonn missing to play in the same league as top universities worldwide? Or does Bonn already belong to them?

Sturm: In Europe, we definitely play a major role already. Our aim is to keep and further develop this position. One advantage of the ETH is, for example, that its significant resources are available in the medium and long run. A short while ago, we did not have this reassurance. Due to the funding of the excellence strategy and the huge support of the University of Bonn and of the government of North Rhine-Westphalia, we will be stronger and well-positioned for the international market. Coming to the United States: I am cautious when it comes to international rankings, especially concerning the high number of US-universities in the top 50. However, the financial means of the universities of Princeton, Harvard and Stanford are well beyond ours. This can be compensated selectively, but the differences cannot be reasoned away, and they also cannot be redeemed by good organization and a lot of effort. In specific areas, however, we are able to keep up with those top universities or are even better which was impressively shown this summer.

What is special about Bonn as a place for mathematics, and what are its strengths?

Sturm: Mathematics in Bonn has evolved into a structure which on one hand establishes a broad foundation, on the other hand, is also impresses by its individual top performers. Firstly, our two Fields medalists in pure mathematics come to mind, who represent Bonn in international research, with our world-renowned Max-Planck Institute as their label. But we also have world-class researchers in other areas - partial differential equations, stochastics, discrete mathematics, numerical simulation, topology, representation theory and a lot more. This is not only a phenomenon of the last couple of years but is due to evolved structures which were systematically strengthened. Here it is crucial that all the different excellent groups benefit from each other and work together as one big team. This made Bonn attractive beyond the German market and subsequently led to more diversity: we could acquire outstanding international researchers, such as Sergio Conti, Juan Velasquez and Massimiliano Gubinelli, for research and teaching. Furthermore, leading German scientists such as Barbara Niethammer, Peter Teichner and Christoph Thiele returned from abroad, and we could successfully prevent brain drain against attractive outside offers to some of our faculty.

Due to the excellence initiative, Bonn receives significant funds. What does Bonn have to offer in exchange? What does the Hausdorff Center do for the mathematical community, especially in Germany?

Sturm: First of all, the kind of basic mathematical research done here poses an advantage for Germany as a hub for science in the long run. From the beginning, we have continued to use much of the funding to benefit the mathematical community - in Germany, but also internationally - mainly by building up the Hausdorff Research Institute for Mathematics, the "HIM". We view this institute as a service facility: applications for programs and participation in the HIM can be done from all over the world, researchers from Bonn do not receive any preferred treatment in this procedure. The structure of the HIM is separate from the structure of the HCM. Furthermore, the program selection is done by an international committee. Geographically, the advantages of the HIM especially benefit German mathematicians. Both junior researchers, who get advanced training for free, and established scientists benefit. The latter especially profit from the possibility of participating in the organization of programs. This allows them to cooperate with the best mathematicians worldwide for four months to discuss topics in a specific mathematical area. Another service facility for the mathematical community is the Hausdorff School for Advanced Studies in Mathematics which has been built up over the last two years and which will expanded significantly during the third funding period. It offers innovative training concepts for postdocs, a form of further education that has been neglected, both in Germany and worldwide, and for which we see a great need. In the future, we plan to organize up to ten times of the week-long summer or winter schools per year. We also offer soft skill seminars such as presentation techniques or interview training and a mentoring program for academic teaching. Most of these offers are available to junior researchers from all over the world, although, for geographical reasons, the community in Germany will probably benefit again.

You mentioned the support for junior scientists. From the beginning, this was one of the most important goals for the Hausdorff Center. Are there more offers to this purpose other than the Hausdorff School?

Sturm: Another important structure is the Bonn International Graduate School of Mathematics, which was built up together with the excellence funding. The positions for PhD students as well as postdocs and junior professors are not given to one specific professor but are advertised worldwide and get occupied competitively, even among working groups of Bonn. We operate on a candidate-driven basis, with annual calls in tune with the US market. The best candidates are supposed to get the position, independently of their specific research area. The BIGS supports PhD students under optimal conditions. They benefit from a widely spread offer of advanced lectures and research seminars and are well connected among each other. Due to the excellence initiative, we could also establish Bonn Junior Fellow positions. We look for junior researchers who are done with their time as a postdoc and have started to develop their own research program. We offer them 5-year W2 professorships with a maximum of scientific freedom, comparable to the Emmy Noether program of the DFG. These attractive positions are announced annually and are allocated in an ambitious selection procedure which we are quite proud of. Within only three months between application and offer, we established a German record here. For some of the positions we also offer a Tenure Track professorship. This program focusses on applicants from all over the world as well. They do not have to speak German by the way. With this, we were successful in attracting outstanding junior scientists even from top universities in the US. Another important point: At least one-third of these positions will be occupied by women. Another tool for the promotion of young scientists is the Junior Trimester Programs at the HIM with a 'bottom-up' structure. Young researchers from all over the world can apply for these, preferably as a group. Over a period of four months, these small groups can work on their own research projects with a maximum of flexibility and can invite top researchers from all over the world. This concept is worldwide unique and provides a lot of dynamics in the mathematical research landscape.

What will be changed in the third funding period? Which structural expansions are planned? Or will everything be continued as before?

Sturm: One point that I already mentioned and that will get quite important now is the Hausdorff School which we want to expand vigorously. Furthermore, we have established a worldwide network which strengthens our present international contacts and which gives them an institutionalized form: the GlobalMathNetwork. Currently, the cooperation partners are the Courant Institute in New York, the École Normale Supèrieure in Paris, and the universities of Kyoto and Peking. All these institutions are having outstanding promotion programs, combined with strong research institutes in the area of mathematics. The GlobalMathNetwork partners allocate sufficient funds to allow their doctoral students to spend at least two months abroad. The students do not necessarily have to stay at a cooperation partner of the GlobalMathNetwork, but when they do, a maximum of support at this location is guaranteed. Particularly, there are no tuition fees. The third change, which we attach great importance to, is the strengthening of cooperation with neighboring sciences. For this, we designed a new program format, the Interdisciplinary Research Units, IRU for short, which are placed on selected interfaces to the related sciences. Embedded into a network of established researchers, coming from both scientific areas, a new group of scientists is built up, typically equipped with a temporary W2 professorship and one postdoctoral and doctoral position each. These IRUs are to be equally financed by both sides. Corresponding cooperations were made with materials science, with mathematical physics and life science, latter even consisting of three of those groups. In the area of life sciences, the associated application procedures have already been initiated together with ImmunoSensation, another Cluster of Excellence in Bonn. The first nomination for a professorship was already received: Professor Hasenauer will concentrate on the development of methods to data-driven modelling of biological processes, together with his work group 'biomathematics'. This allows us to review biological hypotheses and to specifically select future experiments.

What do you wish for the future of the Hausdorff Center?

Sturm: First of all, I hope for the working conditions to continually allow for good mathematical research here in Bonn and that we will be able to attract the best researchers worldwide - as guests or permanently. Furthermore, I expect that we will contribute major results in major problems in mathematics, but also in mathematical problems of society, in the next few years and that we will stay a dynamic project, that is further developing ourselves and prioritizing new topics again and again. We cannot cover all of mathematics, but we should channel our efforts such that we can play an important role in all major questions concerning mathematical research.

First published in German in Mitteilungen der Deutschen Mathematiker-Vereinigung, Band 26, Heft 4, Seiten 170–173, ISSN (Online) 0942-5977, ISSN (Print) 0947-4471,

Translation by Carolin Kaffiné and Jessica Theisen.