Astro Seminar Series - Natalia Porqueres - VIA ZOOM

Natalia Porqueres is a Beecroft fellow at Oxford University, working on cosmology. Her work focuses on understanding the large-scale structures of the Universe. For that, Natalia developed statistical and data analysis tools to optimally extract the information from the observations and make full use of the data. Her methods analyse the data directly at the pixel level and provide constraints on the cosmological parameters and maps of the dark matter distribution. ​Before joining Oxford University, Natalia was a postdoc at Imperial College and did my PhD at the Max-Planck Institute for Astrophysics.

Title: Lifting weak lensing degeneracies with a field-based likelihood

Abstract: With Euclid and the Rubin Observatory starting their observations in the coming years, we need highly precise and accurate data analysis techniques to optimally extract the information from weak lensing data. However, the standard approach based on fitting some summary statistics is inevitably suboptimal and imposes approximations on the statistical and physical modelling. I will present a new method to analyse weak lensing based on a full physics model and field-based statistics. By analysing the data at the pixel level, this method lifts the weak lensing degeneracy and provides uncertainties on the cosmological parameters that are up to a factor 5 smaller than those from standard techniques on the same data. I will discuss the current status and ways to meet the challenges of this approach for its first real data application.