Cosmologie

SEARCHING FOR PRIMORDIAL GRAVITATIONAL WAVES WITH QUBIC: Pipeline development and cosmological constraints

The quest for B-mode polarization of the Cosmic Microwave Background is the primary challenge in Observational Cosmology and is pursued by a worldwide effort. Measurement of B-mode polarization in the CMB will be clear evidence of primordial gravitational waves which are theoretically expected to be produced during inflation at about 10-35 seconds after the Planck epoch. Their presence would be a non-trivial result concerning quantum gravity because tensor modes would mean the metric must be quantized.

Scientific forecasts and participation in the data analysis of the first observations from the Simons Observatory Small Aperture Telescopes

The student will participate in the development and exploitation of the parametric, map-based pipeline for the scientific exploitation of CMB polarization data sets from the Simons Observatory (SO). Although this pipeline is optimized for the detection of primordial B-modes, the intern will lead an effort to measure the performance of the SO Small Aperture Telescopes to detect and characterize E-modes. Beyond their usefulness for calibration and to detect potential systematic effects, E-modes on the largest angular scales could have an important impact on e.g.

À la recherche de l’écho du Big Bang avec le Simons Observatory

Les premiers télescopes du Simons Observatory, au Chili, ont entamé leur prise de données et marquent ainsi le démarrage scientifique de ce projet qui doit s’étaler sur 10 ans et qui vise à effectuer la mesure la plus précise jamais effectuée du fond diffus cosmologique.
 

Detection chain readout development and modeling for next-generation Cosmic Microwave Background observations

The precise characterization of the polarized fluctuations of the 3K Cosmic Microwave Background (CMB) appears today to be a major scientific challenge to further progress in the understanding of the primordial Universe. The so-called cosmological B modes in the CMB polarization are thought to have been generated by inflation in the very early Universe and would provide unique information about the origin of the Universe and fundamental laws of physics at very high energies.

International SciPol internship

We are proposing an undergrad internship in lines of the SciPol (scipol.in2p3.fr) European project, focused on CMB data analysis for the discovery of primordial polarized CMB B-modes. 

The intern will focus on the modeling of specific parts of the detection chain (astrophysical foregrounds, atmosphere, instrument, ground pickup, etc.) and will propose a mitigation technique associated to this specific effect. 

Probing Dark Energy with Euclid Cluster Observations

The European Space Agency’s (ESA) Euclid space mission aims to reveal the nature of dark energy, the mysterious cause of the observed accelerated expansion of the universe. Identifying dark energy is arguably the most profound question facing fundamental Physics today, because of its connection between the quantum world and gravity. Euclid will measure the dark energy equation-of-state (EoS), which is to say that it will determine if dark energy is constant or varies with time, a key distinction for theoretical understanding.

SciPol internship (M1)

We are proposing a M1 internship to work on the component separation of the LiteBIRD space mission. It will involve the handling of python codes, CMB and astrophysical signals simulations, as well as the learning of the basics of CMB data analysis. 

This internship would be part of the global effort undertaken by the SciPol project: https://scipol.in2p3.fr/

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 cluster cosmology the cluster selection function should known with great precision.
 

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.
 
Cosmologie