Happy „International Women in Math Day“! Sarah Wolf: An Interdisciplinary Mathematician and her Film Portrait on “Decision Theatre“

Photo: Sarah Wolf - Decision Theatre (Futurium), © Kay Herschelmann / MATH+

Sarah Wolf has been MATH+ Junior Research Group Leader of the research group “Mathematics for Sustainability Transitions” at Freie Universität Berlin since 2019 and leads the “Schule@DecisionTheatreLab”, a project funded by the Berlin University Alliance (BUA) and MATH+. There is now her film portrait on a mobility model and the “Decision Theatre”, produced by the Berlin University Alliance, which MATH+ is releasing today to celebrate “International Women in Math Day.”


When asked about her interest in mathematics, she laughs and says she has a family predisposition towards it, as both her parents studied mathematics. Even in school, it was one of her favorite subjects. That’s why she knew as early as 10th grade that she wanted to study mathematics. However, she didn’t want to add a standard subject like computer science or economics. And since she had already spent a year in Italy, Italian became her master’s minor for her math degree at Humboldt Universität.


Concerning the “International Women in Mathematics Day,” she felt the same as many of her fellow female students: “When we started our studies, we were about 25% female students, and there were only a few female researchers. I didn’t experience any female professors at all while studying, only in the broader community.” However, there are now more and more women mathematicians in her math department at Freie Universität and the neighboring Zuse Institute Berlin. Asked about her female role models in math, she said that she respected and admired the mathematician Emmy Noether (1882-1935), who already then became famous for her mathematics.


She wrote her thesis on an application in paleoclimate research about data from ice cores. It was the first time she applied mathematics in a climate context, which she pursued further in her PhD at the Potsdam Institute for Climate Impact Research (PIK). This is also where her specialization in sustainability issues began. She used mathematics as a language to clarify concepts around vulnerability to climate change. Afterwards, at PIK she worked on economic issues around the topic of Green Growth, that is how climate policy can be beneficial also for the economy and hence people.  This research was done with agent-based models (ABM), which are Sarah Wolf’s current research field.


Agent-based models are used by many disciplines, e.g., in ecology, where the modeled individuals represent plants or bacteria, in archaeology, in modeling the spread of infectious diseases etc. In many models, the agents are actually people, but in economics, for example, they can also be firms. Simulations with ABM are helpful, e.g., during the Corona pandemic, but it is often not possible to prove mathematically how they behave precisely. This, however, is exactly what is exciting for Sarah Wolf. She wants to be able to mathematically formulate an existing model so that she can then theoretically analyze and better understand it. But she also sees the usefulness of simulations: “These large models have their uses when you want to represent a society and analyze policies. We also use them in the DecisionTheatre (DT)”, Sarah Wolf’s second major area of research. A Decision Theatre is a workshop in which scientists, expert stakeholders, and citizens discuss a societal challenge and can use data and simulation results displayed on several big screens at the same time.


Photo: © Kay Herschelmann / MATH+

Sarah Wolf has been involved with Decision Theatre (DT) for five years and developed a large mobility model in Germany (MoTMo) with her research group at the Global Climate Forum (GCF) in Berlin. She explains this model in her portrait film, produced by the Berlin University Alliance (BUA). Based on the model, a Decision Theatre was designed with a research group of the Arizona State University, which already gained a lot of experience with DT’s. Since then, Sarah Wolf has been using the model in the Decision Theatre for science communication on the one hand and for her research on the other, as feedback from participants in DT’s helps to improve the model.



Photo: © Beate Rogler / MATH+

After a call for proposals by BUA for “Experimental Science Communication Laboratories”, the school project “Schule@DecisionTheatreLabwas launched together with MATH+, because of its rich experience with school activities. It aims at exchanges with students from grade 10 onwards, starting with an agent-based “Decision Theatre” on “Sustainable Mobility,” which already existed and could easily be adapted for school students to create a more interactive version. The second DT on “Spread of Infectious Diseases” is currently being designed. It is based on the GERDA model developed by scientist and MATH+ member Edda Klipp and her research group at Humboldt Universität zu Berlin. To make the Decision Theatre more tangible for students, it is accompanied by two workshops in the so-called “DT Lab”: one workshop exemplifies the mathematics behind the models on a very simple model, and the other one shows how students can change the code on a very simple model framework to add their own ideas. In total, ten mobility DT’s have already been held with school students, three for university students of math education as an inspiration for school use, and two for the general public, for exmaple one in the FUTURIUM, to get to know the DT.


Sarah Wolf describes her career as rather atypical for mathematicians, as she has always worked in interdisciplinary teams from the time of her doctorate onwards and has long focused on economic agent-based modeling. There needs to be more time for the mathematical investigation behind the models, she says somewhat regretfully, as Decisio Theatre is in high demand and takes up a lot of time. Thus, there is still much to do in her research topics. Funnily enough, the mother of four children, including triplets, took them as inspiration for the idea of a “digital triplet” that extends the “digital twin” concept, where a technical system feeds data into its digital model and the model gives back optimized controls. For a societal system, digital control would neither be possible nor desirable; therefore for the digital triplet people come together in the DT to discuss possible policies with the help of the model.


She finds ABM extremely exciting for describing societal challenges in the context of sustainability, be it mobility, a heat transition, or questions of green growth. Increasingly important is that DTs can be carried out by larger groups and the broader society, and that everyone is actively involved via small group discussions. In addition to students, mathematically interested people of all ages and stakeholder groups from politics, business, and journalism should be involved. This idea is work in progress. In any case, this is a promising plan that hopefully can be implemented in the near future!


„The International Women in Mathematics Day“, first established in 2019, celebrates women in mathematics in honor of Iranian mathematician Maryam Mirzakhani (1977-2017), who was the first woman to win the Fields Medal, the most prestigious award in mathematics.