Cosmologie

Matrices de bolomètres supraconducteurs pour la mesure de la polarisation du fond diffus Cosmologique

L’étude des fluctuations polarisées du rayonnement fossile à 3K (Cosmic Microwave Background, CMB) apparaît aujourd’hui comme une voie incontournable pour progresser dans notre compréhension de l’Univers. Le niveau de signal attendu, quelques nK pour le mode B le plus faible, requiert une chaîne de détection à la fois ultra sensible et extrêmement immune aux effets parasites instrumentaux.

Characterisation of Kinetic Inductance Detectors suitable for polarisation measurements at 150 GHz

A first generation of polarisation-sensitive kinetic inductance detectors operating at 150 GHz is ready to be tested at 300 mK. These devices are deployed in small (20-25 pixels) arrays, suitable for a thorough understanding of the response of individual detectors. At APC - Laboratoire Millimétrique a fully equipped test bench is available for vectorial measurements and for photometric measurements: both these techniques are needed for a full characterisation of these devices.

Composite dark matter of the Universe

Problems of direct searches for simplest Weakly Interacting massive particles of dark matter lead to more complex solutions for thsi exciting problem.

L'optimisation de l'expérience BAO radio HIRAX

L'une des questions les plus importantes de la cosmologie contemporaine est la nature de l'énergie noire (dont la découverte était à l'origine du Prix Nobel de physique 2011). L'énergie noire s'explique-t-elle par une constante cosmologique ou par une forme d'énergie encore plus exotique ?

Preparing Dark Energy Studies with Euclid: Simulating Images

Dark energy and dark matter are the great mysteries in cosmology today. Understanding the distribution of dark matter in the Universe and obtaining strong constraints on the nature of dark energy and its possible origins are the main goals of ESA’s dark energy mission Euclid.

The primary objective of cosmological research in the coming decade is to understand the accelerated expansion of the Universe.  Is it caused by a new cosmic component commonly called dark energy or a modification to General Relativity?  The abundance of galaxy clusters as a function of their mass and its evolution with redshift is a sensitive probe of the expansion rate and of structure formation.  Detecting and counting clusters is therefore an observational method probe of both dark energy and of possible modifications to General Relativity.