Periodic Reporting for period 4 - GrInflaGal (Gravity, Inflation, and Galaxies: Fundamental Physics with Large-Scale Structure)
Période du rapport: 2021-03-01 au 2022-08-31
Significant progress was further made on rigorously understanding the impact of single-field inflationary models, the simplest inflationary scenario, on the statistics of large-scale structure. Theoretical advances in the modeling of tidal alignments have also been made.
With the advances in simulation and theoretical approaches described above, the modeling of observables in large-scale structure is nearing completion. However, two challenges need to be surmounted in order to obtain constraints on gravity and inflation: a) the covariance (error bar) of observables such as the weak lensing power spectrum needs to be understood; b) in case of galaxy clustering, it has become very clear that including higher-order statistics is essential. Measuring these becomes increasingly complicated and costly however. The PI's team has made progress in developing novel methodology to deal with both challenges: the PI's team developed the response approach to covariances of large-scale structure observables, which has greatly advanced the state of understanding and simplified their calculation. In a separate direction, significant efforts of the PI's team, are devoted to developing optimal inference approaches to large-scale structure which avoid complicated and costly measurements of higher-order statistics. These approaches go far beyond the current state-of-the-art in the field, which is restricted to two-point functions, and will have a significant impact on both research goals. A first proof of concept and quantitative results were published in 2019.
The next goal is to take this methodology closer to the application to data, by including physical and observational effects that need to be included step by step. Finally, an application to large survey data sets should then yield competitive and extremely robust constraints on gravity and inflation.