Astrophysics Seminar

Probe combination: Greater than the sum of its parts

Speaker: Alexander Reeves (ETH Zurich)

Date and time
A&A Lecture Hall


In the last decade, we have significantly improved our understanding of the cosmological model describing our Universe's evolution primarily due to advances in the quality and volume of survey data. The probe combination technique has been shown to be a powerful method of analyzing modern wide-field surveys. That is, by measuring the correlation between data from different surveys, we can isolate signals robust to systematic errors. Additionally, because different cosmological probes are sensitive to different physical processes, we can break degeneracies in the cosmological model parameters enabling tighter constraints. In this talk I will present a new pipeline for simulation-based multi-probe analyses, which combines tomographic large-scale structure (LSS) probes (weak lensing and galaxy clustering) with cosmic microwave background (CMB) primary and lensing data. These are combined at the Cℓ-level, yielding 12 distinct auto- and cross-correlations. The pipeline has been applied to forecasting neutrino mass constraints from the combination of CMB (Planck), Weak Lensing (KIDS) and Galaxy clustering data (BOSS). In this talk I will outline the results of this forecast study as well as some preliminary results on real data. This talk is based on some of the results outlined in