PhD candidate Clara Stegehuis wins KWG PhD prize

Clara Stegehuis, PhD candidate in the Stochastic Operations Research group, has been awarded the KWG PhD prize at the Dutch Mathematical Congress last week. Stegehuis was one of four nominees who held a presentation about their research during the congress. Her presentation on networks and epidemics convinced the jury to choose her as this year’s winner of the KWG PhD prize.

General public
An important criterion for winning the award was the PhD candidate’s ability to make the subject accessible to non-specialists. Therefore the presentation had to be aimed at a general mathematical audience. A requirement Stegehuis is familiar with, since she is one of the Faces of Science bloggers, and she regularly gives lectures on mathematics to a wider audience.

How community structure affects epidemics
In her talk, Stegehuis illustrated the importance of using community structures, groups of densely connected vertices (points where two or more curves, lines, or edges meet), in network models. She did so by introducing a random graph model that includes community structures, investigating how an epidemic process spreads over the network model, and comparing this to the behavior of the same process on traditional random graph models without community structures.

Interestingly, community structures speed up the spread of an epidemic in some networks, but slow it down in other networks, depending on the exact community shapes. This underlines the importance of using community structures.