You have been an Oskar Klein Fellow for more than 2 year, how is it going so far?
I am very much enjoying working at the OKC. In particular, the inspirational atmosphere within the centre is very fruitful for my work. I adjusted easily to the Swedish climate (especially the short winter days) and I love living in Stockholm.
Why did you choose the OKC for doing a postdoc?
The most compelling feature of the OKC is the broad spectrum of astroparticle physics subjects addressed by the OKC researchers. In particular, the interplay between experimental, phenomenological, and theoretical physics is very appealing to me. My Ph.D. focused on experimental cosmic-ray physics and phenomenology. The OKC gives me the opportunity to continue working in both areas (within the astroparticle group at KTH and the CoPS group at SU) while simultaneously broadening my knowledge base to other fields, such as indirect searches for dark matter.
What is your field of research? Can you describe the project/projects in which you are involved?
My primary research area is cosmic-ray physics. I focus on the study of the acceleration and propagation processes of Galactic cosmic-rays, but also to constrain the dark-matter properties through indirect searches. These subjects are a natural continuation and expansion of my Ph.D. work.
On a more detailed level, I study cosmic-ray particles (nuclei, leptons, and gamma-rays) produced in the Galaxy either in high-energetic sources (primary sources), such as supernova explosions, or through interaction with the interstellar medium (secondary sources) as well as through hadronisation processes of dark-matter annihilation products (exotic sources). The latter contribution can be seen as an excess in the cosmic-ray spectrum. The propagation and acceleration mechanisms can be studied with help of cosmic-ray secondary-to-primary ratios (e.g., boron/carbon) and primary fluxes (e.g., carbon), respectively. Juan Wu, Mark Pearce, and I are currently analysing cosmic-ray data with a known propagation code for that purpose. The aim of this study is to estimate the power of the published PAMELA data to constrain the source and transport parameters of the cosmic-ray propagation models within a Bayesian framework.
One of the most promising cosmic-ray target populations for indirect dark-matter searches are anti-deuterons. Even though their predicted flux is weak, the dark-matter contribution is more readily separated from the astrophysical background contamination than for e.g., antiprotons and positrons. Together with Joakim Edsjö, Natallia Karpenka, Christopher Savage, and Pat Scott we are currently investigating the detection power of ongoing and future measurements of anti-deuterons originating from annihilating supersymmetric dark-matter particles.
What do you find unique for your field of research about the OKC?
The interaction between experimental and theoretical groups with a broad coverage of different astrophysical subjects is rare and therefore more valuable. Multi-messenger approaches are becoming more prominent within astroparticle physics, and the OKC is taking an important role in developing novel approaches for applications to dark-matter searches, e.g. the supersymmetric global fit effort, in which I am also involved.
What is your story before the OKC?
I was born in East-Berlin, Germany. After the Wall came down, I was given the opportunity to go to a French-German school, where I was inspired to participate in a double-diploma exchange programme supported by the Franco-German University. This kind of exchange allows one to study in two countries, experience two cultures, and obtain two diplomas simultaneously. Only a few universities in Germany and France offer such an exchange in Physics. Initially, I studied for three years in Karlsruhe (Germany) before transferring to Grenoble (France) for my Master’s degree, Diplomarbeit (German diploma), and Ph.D..
During my studies in Karlsruhe, I took the astroparticle course given by Jörg Hörandel. The topic of cosmic rays captured me immediately. During one class, he showed us pictures from the launch of the balloon-borne TRACER experiment in Antarctica. Little did I know, that only five years later I would get the opportunity to travel to Antarctica myself. Indeed, I prepared and assisted the launch of the CREAM (Cosmic Ray Energetics And Mass) experiment during my last year of my Ph.D. with Laurent Derome,
What plans do you have for the future?
Sadly, my time at the OKC will be over in half a year. I certainly want to continue working in research. Accordingly, I am currently applying internationally for various positions in cosmic-ray physics. I will also continue working on various ongoing and hopefully new projects with the members of the OKC.