Colloque national CMB-France #1

Session

Open session

2 juin 2021, 14:50

15. Impact of polarised extragalactic sources on the measurement of CMB B-mode anisotropies

Guilaine Lagache (LAM)

02/06/2021 14:50

Using state-of-the-art models of galaxy evolution for both radio and dusty galaxies and polarisation fractions as recently measured, we computed the B-mode power spectra of the three extragalactic foregrounds: radio source shot noise, dusty galaxy shot noise, and clustering. We will discuss their relative levels for different CMB experiments and will compare their amplitudes to that of the...

9. Phase harmonics statistics and denoising/components separation

Erwan Allys (LPENS, Paris)

02/06/2021 15:10

Phase harmonics statistics are recently developed non-Gaussian statistics, inspired by convolutional neural networks, which characterize the interaction between scales in a given process. It is possible to build from these statistics a realistic generative model of a process from a very limited number of samples. In this talk, I will show how this possibility has allowed the development of new...

12. Phase-harmonic generative models for likelihood-free polarization foreground marginalization

Dr Niall Jeffrey (École normale supérieure)

02/06/2021 15:30

I will present single frequency morphological foreground removal and denoising using deep learning (in a Bayesian likelihood-free framework) using phase harmonic augmentation. With only a single training image of polarized dust foregrounds, we are able to generate new realisations using wavelet phase harmonic synthesis. In a likelihood-free inference framework, these new realisations can be...

11. Cosmology with the T-E correlation coefficient

Adrien La Posta (IJCLab, CNRS, France)

03/06/2021 16:10

Precise measurements of cosmological parameters have revealed tensions in the standard model of cosmology. One way of studying these tensions is to check the robustness of our datasets using observables that are less sensitive to systematic effects. In this talk I will discuss the properties of the Pearson's correlation coefficient of T and E modes $\mathcal{R}_\ell^{TE}$; a combination of the...

5. Moment expansion: a new path towards capturing the CMB B-modes with LiteBIRD

Léo Vacher ({UNIV TOULOUSE PAUL SABATIER}UMR5277)

03/06/2021 16:30

In the quest for the Cosmic Microwave Background (CMB) primordial $B$-modes, being able to accurately characterise the polarised foregrounds will be decisive. The mismodeling of their complex spectral properties could lead to a bias on the final estimation of the tensor-to-scalar ratio $r$. Finding a method to avoid this issue is central for future key surveys like the LiteBIRD satellite,...

6. NIKA2

Juan Francisco Macias-Perez (LPSC)

03/06/2021 16:50

Analyses NIKA2

10. Better accounting for reionisation in CMB data analysis: the KSZ effect

Adélie Gorce (Institut d'Astrophysique Spatiale)

03/06/2021 17:10

CMB data is a crucial source of information about reionisation. Despite the exquisite measurements of Planck on large scales and SPT, ACT or future CMB-S4 experiments on small scales, the way CMB data is currently used to constrain reionisation is coarse.
In this talk, we focus on the kinetic Sunyaev-Zel’dovich effect in the context of patchy reionisation and introduce a new way to relate...

18. Detection of the kinetic Sunyaev-Zel'dovich effect in galaxy clusters with Planck data

Hideki Tanimura (Institut d'Astrophysique Spatiale)

03/06/2021 17:30

The kinetic Sunyaev-Zel'dovich (kSZ) effect is caused by the scattering of CMB photons off the electrons due to the object's bulk motion. It is proportional to the peculiar velocity but also depends on the properties of the virialized gas as well as the gas surrounding halos.

I will present the statistical detection of the kSZ effect from ~30,000 galaxy clusters identified in the SDSS...