Large Scale Structure at the Field Level
The distribution of galaxies on large, cosmological scales holds important clues about dark matter, dark energy, and the origin of our Universe. New surveys, such as DESI and Euclid, are mapping this distribution at an unprecedented volume and depth. Yet, optimally retrieving information from the observations is challenging. My team is developing a novel strategy called field-level analysis. We follow the evolution of cosmic structures from the very early Universe all the way up to their detection by combining perturbative methods - particularly the Effective Field Theory of Large Scale Structure - with careful modeling of observational effects. Such a forward model will allow us to compare theoretical predictions with the data at the level of the three-dimensional density field, thereby maximizing the information extracted and providing insights into the dark matter structures that surround us.
There is also a detailed outreach article available.
Further research interests
Deep Interferometric Imaging of the Galactic Center
The Galactic Center is home to Sagittarius A*, the closest supermassive black hole to Earth. By precisely tracking the orbits of stars around this black hole, the GRAVITY interferometer provides unique tests of General Relativity in the strong regime — confirming effects like gravitational redshift and Schwarzschild precession. Deep imaging is essential in the quest for faint stars close to the black hole, but is complicated by the complexity of the measurement process and the instrument. We developed the GR algorithm using forward modeling and a Bayesian machine learning framework called Information Field Theory to achieve high-resolution images that are very sensitive to faint details. Its application led to the discovery of a new star, now called S300.
Dark Matter microphysics constrained by the CMB
The Cosmic Microwave Background (CMB) provides a snapshot of the universe during a period when it was significantly hotter and denser. It offers vital clues about the existence and properties of dark matter. We investigate how the CMB radiation would be affected if dark matter, instead of being entirely cold and collisionless, exhibited weak interactions with photons or neutrinos. Comparing our predictions to measurements by the Planck satellite, we constrained the maximum strength of such interactions to learn more about dark matter microphysics.
