Kippenhahn Prize 2018 for single author paper by Aoife Boyle

Established in 2009 by former director Prof. Rudolf Kippenhahn, the prize is awarded to the best MPA student paper to motivate students. The student has to be first author and needs to have contributed substantially to the scientific ideas, calculations and analysis, and the writing of the paper. For 2018, the committee had to choose between eight papers, which were all very good. Nevertheless, the committee agreed unanimously that one paper stood out – and it was written by a single author: Aoife Boyle combined two techniques to constrain the neutrino mass.

Massive neutrinos affect the cosmic structure formation in a number of ways, via the expansion rate of the Universe, the growth rate of density fluctuations, and the scale-dependent modification of the power spectrum due to neutrino free-streaming. The large-scale structure observations have been used to constrain the neutrino mass, but the researchers did not understand where the constraints came from or how the constraints depended on the assumed cosmological models. Boyle’s paper for the first time clarifies how the constraints depend on cosmological models, and show how to use the neutrino free-streaming signature to constrain the neutrino mass in a model-independent manner. Her paper also shows how the popular combination of the data sets, the Baryon Acoustic Oscillation combined with lensing of the cosmic microwave background, wastes a great deal of information, and the free-streaming signature in the galaxy power spectrum offers promising model-independent constraints on the neutrino mass.