About

I am an Einstein Postdoctoral Fellow in the X-ray Astronomy and Observational Cosmology group at SLAC / KIPAC / Stanford University. Before that I was a PhD student [1] and post-doc at University Observatory Munich and the Max Planck Institute for extraterrestrial Physics.

My main research interests are weak lensing studies of large structures in the Universe such as clusters of galaxies [2,3,4,5], which can give us a better understanding of the physics of the two big mysteries of modern cosmology, dark matter and dark energy. I am co-coordinator of the weak lensing working group of the Dark Energy Survey, which has recently presented its first competitive cosmological constraints [6,7,8,9].

I have worked on developing new ways of measuring shapes of faint background galaxies. I have also done the actual data reduction and weak lensing analysis of a number of clusters of galaxies, among them the pictures you see on top of this page. I have developed new statistical methods for weak lensing, especially for estimating and calibrating photometric redshifts [10,11]. I have devised a new density split statistic to measure the full PDF of the matter density field [12] and used those measurements for new tests of gravity and improved constraints on cosmology [13,14]. In the course of this work, I also got interested in the correction of instrumental features [15] required for precision analyses.