22–26 Aug 2022
Rio de Janeiro
America/Sao_Paulo timezone

The lensing amplitude $A_L=1$ is not a good cosmological parameter for the $\Lambda$CDM model

22 Aug 2022, 14:20
20m
Rio de Janeiro

Rio de Janeiro

Vice-Governador Rúbens Berardo street, 100 - Gávea Rio de Janeiro - 22451-070
Plenary/Parallel talk Large scale structure Parallel Session Main Cupula: DM

Speaker

Armando Bernui (Observatorio Nacional)

Description

Precise measurements at small angles of the cosmic microwave background (CMB) angular power spectrum (APS), done by the Planck collaboration, have stimulated accurate analyses of the lensing amplitude parameter $A_L$ to confirm if it satisfies the value expected by the flat $\Lambda$CDM concordance model, i.e. $A_L = 1$.
We discuss a possible excess in the Planck APS not accounted by the $\Lambda$CDM APS. Firstly, we test the hypothesis that the residual APS (i.e., the measured APS minus the $\Lambda$CDM APS) is white noise, or not. Then we quantify how much lensing amplitude is lacking in the Planck analyses of the flat $\Lambda$CDM concordance model (with $A_L = 1$ as a premise). We find that, indeed, there is a residual gravitational lensing signal that is well explained as a lacking lensing amplitude, in the $\Lambda$CDM APS, of around 15%.

Primary authors

Presentation materials