Cosmologie

Simulations of observations for a proposal for a future spectroscopy space mission

The next generation of space surveys in cosmology and galaxy evolution will focus on the questions that Euclid, the Roman Space Telescope and the Legacy Survey of Space and Time (LSST) will not resolve.

Simulations of observations for a proposal for a future spectroscopy space mission

Inauguration en Argentine de l'Observatoire QUBIC

Observatoire QUBIC : Vue aérienne lors de l’inauguration Crédit : MINCyT
Le 23 novembre l’Observatoire QUBIC a été inauguré avec un grand succès.

Cosmology dependence on the covariance of galaxy clusters in Rubin/LSST

The covariance of galaxy clusters is an important element when constraining cosmology with galaxy clusters. However its computation is costly in computational resources, especially when it depends on cosmology. We propose an evaluation of the impact on the cosmological parameters when the modeling of the cluster covariance is simplified. This is one of the projects for the preparation of the LSST-DESC cluster cosmology framework.

Impact of the mass function on galaxy cluster constraints for cosmology in Rubin/LSST-DESC

The abundance of galaxy clusters is a powerful probe for cosmology, especially on large-scale surveys. The goal will be to evaluate the impact of the different mass functions used for the theoretical prediction of cluster counts on the cosmological constraints. This project will be done for the preparation of the LSST-DESC cluster cosmology framework.

Dection of the Global 21cm Signal With REACH

The 21 cm HI transition offers a window onto the reionization history of the universe and the formation of the first generation of stars and quasars, when the universe was still metal poor. The global 21 cm signal consists of the non-Galactic distortion of the CMB blackbody radiation through absorption or emission by HI (atomic hydrogen) depending on whether the HI spin temperature is less or greater than the CMB temperature. Recently the EDGES experiment has detected a large signal that appears incompatible with existing theoretical models.

Infationary non-Gaussianities in the CMB and large-scale structure

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

The quest for B-mode polarization of the Cosmic Microwave Background is among the main challenges in Observational Cosmology. Measurement of B-mode polarization in the CMB will be clear evidence of the presence of primordial gravitational waves which are theoretically expected to be produced during inflation about 10-35 seconds after the Planck epoch.

Machine Learning for Photometric redshift estimation of LSST galaxies

Machine Learning techniques have revolutionized artificial intelligence. Their application to astrophysics and cosmology permits us to analyze the large quantity of data obtained with current surveys and expected from future surveys with the aim of improving our understanding of the cosmological model.

Probing Dark Energy with Galaxy Clusters: The Euclid Galaxy Cluster Catalog

The primary objective of cosmological research in the coming decade is to understand the accelerated expansion of the Universe, attributed to either a dark energy component or a modification to gravity on cosmic scales. This thesis will focus on evaluating the Euclid galaxy cluster selection function, an essential element of using the mission’s cluster catalog as a probe of dark energy and modified gravity.

Cosmologie