Modelling CMB lensing and galaxy surveys cross-correlations for next generation surveys

Jul 15, 2019 - 11:00 am to 12:00 pm

Campus, Varian 355

Giulio Fabbian (University of Sussex)

The cosmic microwave background (CMB) gravitational lensing and its cross-correlation with large-scale structure tracers will be important cosmological probes in the coming years. Being able to model these observables and reconstruct them from the data with the level of precision required by future experiments will be mandatory in order to exploit them for robust cosmological applications.

I will present recent theoretical and numerical developments in the modeling of CMB lensing including the non-linear evolution of the matter distribution and consequences of multiple lensing deflections of photons. I will show how these effects propagate in the statistical estimators of CMB lensing and how they can affect the inference of cosmological parameters. I will show that these effects are more important for CMB lensing cross-correlationĀ  with large scale structures tracers and they can effect our ability to use cross-correlation with CMB to marginalize systematic effect in galaxy surveys. Finally I will discuss how we can model these biases analytically and reduce their effect in the analysis of future experiments such as Simons Observatory, CMBS4, Euclid, LSST.