Cosmologie

Exploration and visualisation of fluctuations of cosmic microwave background anisotropies

The objective of the internship is to familiarize the student with modern cosmology and particularly with the physics, informational content, as well as practical applications and observations of the fluctuations of the cosmic microwave background (CMB). The student will explore different observational techniques and approaches used for observations of the CMB and critically compare them. The student will learn to use and compare multiple numerical codes developed by the community in order to generate simulated maps of the CMB sky and explore the impact of beam effects on them.

Cluster cosmology with LSST

Galaxy clusters are the most massive dark matter halos in the Universe. They host galaxies, gas, dust and dark matter.
 
The Legacy Survey of Space and Time (LSST; https://www.lsst.org/about) will detect hundreds of thousands of clusters, which can be used to constraint cosmology and study galaxy evolution. For cosmological study we need a very precise determination of the cluster selection function.
 

Measurement of CMB B-mode polarisation with the LiteBIRD satellite mission: development of innovative data analysis techniques.

The Cosmic Microwave Background (CMB) radiation is a relic emission from 380 000 years after the Big-Bang at the time of decoupling between matter and radiation. The small CMB temperature and polarisation fluctuations, induced by quantum perturbation generated in the early Universe, contain precious information about the physics of the primordial Universe and its physical content. Several experiments, including the Planck satellite mission of ESA have measured those perturbations with high accuracy, leading to per cent precision on the determination of cosmological parameters.

Measurement of CMB B-mode polarisation with the LiteBIRD satellite mission: development of innovative data analysis techniques.

The Cosmic Microwave Background (CMB) radiation is a relic emission from 380 000 years after the Big-Bang at the time of decoupling between matter and radiation. The small CMB temperature and polarisation fluctuations, induced by quantum perturbation generated in the early Universe, contain precious information about the physics of the primordial Universe and its physical content. Several experiments, including the Planck satellite mission of ESA have measured those perturbations with high accuracy, leading to per cent precision on the determination of cosmological parameters.

CMB Foreground Studies

Measurements of the Cosmic Microwave Background (CMB) have transformed cosmology into a precision science, and they continue to deliver new insights into the birth and evolution of our Universe. One of the major hurdles in extracting these insights, however, come from "foreground" signals emitted from intervening matter. These spurious emissions can mask and even mimic the primordial CMB, introducing errors into our conclusions.

Diffuse gas in LSST clusters

Galaxy clusters are the most massive dark matter halos in the Universe. They host galaxies, gas, dust and dark matter.
 
Recently, cluster diffuse gas has provided important information about the feedback activity of their galaxies and gas accretion from filaments.
 
The Legacy Survey of Space and Time (LSST; https://www.lsst.org/about) will detect hundreds of thousands of clusters, which can be used to constraint cosmology and study galaxy evolution.
 

Cosmology with Rayleigh scattering of the CMB

Rayleigh scattering of the Cosmic Microwave Background (CMB) is a less studied yet potentially powerful probe of the recombination history. Scattering of CMB photons off neutral species right after recombination presents a distinctive $\nu^4$ scaling with frequency as well as a strong correlation with the primary CMB. These unique features should facilitate its detection by the next generation of CMB experiments.

SciPol internship

We are proposing a L3 internship to evaluate our ability to characterize instrumental parameters (in particular intensity-to-polarization and cross-polarization effects) within an updated component separation framework. This internship would be part of the global effort undertaken by the SciPol project: https://scipol.in2p3.fr/

Optimisation du système de contrôle et d’acquisition d’une expérience de détection du rayonnement fossile à 10GHz.

Le rayonnement fossile à 3K est la première lumière de l’Univers et a été émis environ 380000 ans après le Big Bang. Il possède un spectre de corps noir avec une température d’environ 2.73K et peut ainsi être observé dans la gamme de longueurs d’onde millimétriques. Le rayonnement fossile fait l’objet d’intenses recherches en cosmologie observationnelle, en particulier au niveau de la polarisation qui renfermerait les traces de l’inflation, une phase d’expansion exponentielle de l’Univers aux tous premiers instants.

Pages

Subscribe to RSS - Cosmologie