Cosmologie

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.

The APC Laboratory mourns the loss of George Smoot, who passed away unexpectedly at his home in Paris. George Smoot was one of the pioneers of observations of the cosmic microwave background (CMB), which revolutionized our understanding of the cosmos and placed cosmology on a firm experimental footing. (Credits photo: Peter Badge/Lindau Nobel Laureate Meetings)

Ce stage offre une initiation aux techniques d'analyse des données astrophysiques liées au fond diffus cosmologique (CMB). Il permettra à l’étudiant.e de se familiariser avec les méthodes utilisées pour explorer et interpréter les informations contenues dans ces observations provenant de l'Univers primordial. Le projet se concentrera en particulier sur l’optimisation des techniques dites de séparation de composantes, qui distinguent le CMB des contaminations galactiques.

Dans le cadre de la préparation des données du télescope LSST de l’observatoire Vera C. Rubin qui fear sa première lumière en 2025, l’un des défis majeurs est le deblending des galaxies, c’est-à-dire la séparation des contributions lumineuses de galaxies superposées dans les images astronomiques.

According to the standard cosmological model, about 95% of the Universe's energy content is in two unknown forms: dark energy, responsible for accelerating cosmic expansion, and dark matter, the predominant form of matter. Understanding these components is one of the key challenges in modern physics and cosmology.

During the last decade, cosmology has entered a precision era, leading to the prevalence of the standard cosmological model, ΛCDM. Nevertheless, the main ingredient of this model, the so-called dark energy, remains mysterious while dominating the energy budget of the Universe. Its comprehension is therefore one of the main goals in this domain.

Observations of the Cosmic Microwave Background fluctuations provide a unique view onto the early Universe and the fundamental laws of physics at the most extreme energies (typically twelve orders of magnitude above what could be achieved at the Large Hadron Collider). The successful European-led space mission Planck provided the ultimate characterization of the CMB fluctuations in total intensity and a robust detection of some of the polarization signal.