Quest for primordial gravitational waves: advanced map-making for the next generation of CMB B-mode polarization data sets.

Many popular theories of the early Universe predict that gravitational waves were generated in the very first moments of its life. These theories generally invoke new physics from beyond the standard model of the particle physics and the primordial gravitational waves are believed to carry clues about the nature of those new physics laws. Detecting the primordial gravitational waves would thus have revolutionary impact on our understanding of cosmology and fundamental physics.

Quest for primordial gravitational waves: advanced data analysis for the next generation of CMB B-mode polarization data sets.

Many popular theories of the early Universe predict that gravitational waves were generated in the very first moments of its life. These theories generally invoke new physics from beyond the standard model of the particle physics and the primordial gravitational waves are believed to carry clues about the nature of those new physics laws. Detecting the primordial gravitational waves would thus have revolutionary impact on our understanding of cosmology and fundamental physics.

Planck/LiteBIRD Phd Opportunity

This PhD project focuses on the physics of the Cosmic Microwave Background both from an observational and from a theoretical perspective. This PhD will be co-supervised by Martin Bucher and Ken Ganga at APC in Paris. It is also envisaged that the student will take part in exchanges with researchers at the University of Tokyo.

Weak lensing with multi-surveys joint analyses for dark energy studies.

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, dark energy, while dominating the energy budget of our Universe, remains mysterious and its comprehension is the current Graal of the domain.

Architecture instrumentale optimisée pour la mesure de la polarisation du rayonnement fossile

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.

Performances de l’instrument QUBIC 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.

Multichroic detectors for Cosmic Microwave Background polarisation observation

To optimise the optical performances of a future space instrument dedicated to CMB polarisation observations, it will be very interesting to reduce the physical size of the focal plane without decreasing the number of detectors. An elegant way to reach such architecture would be to use multichroic detectors that are sensitive to multiple frequency bands. A large bandwidth antenna could be used to feed multiple detectors (TESs or KIDs) through different bandpass filters.

Détecteurs multi-fréquences pour l’observation de la polarisation du rayonnement fossile

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. Après Planck, la communauté européenne étudie actuellement deux options dans le cadre d’une mission spatiale dédiée à la caractérisation de la polarisation du ciel sub-millimétrique et millimétrique: une participation à la mission spatial japonaise LiteBird d’une part et l’optimisation du concept d’instrument spatial COrE+ en vue de l’appel d’offre ESA M5 d’autre part.

Cosmic Microwave Background Polarization Studies

Spider is a balloon-borne experiment designed and flown to study the cosmic microwave background. More information about Spider can be found at http://www.princeton.edu/jones/research/spider/.

Exploring the primordial Universe, inflation and primordial Gravitational Waves with QUBIC, the QU Bolometric Interferometer for Cosmology

The quest for B-mode polarization of the Cosmic Microwave Background is among the most promising topics in Observational Cosmology as it would sign the presence of primordial gravitational waves hence opening a window on the inflation era. It also one the most challenging as the expected is very small and require high sensitivity and low systematic instruments with wide frequency coverage in order to separate the primordial signal from foreground emissions.

LABORATOIRE

ASTROPARTICULE & COSMOLOGIE

Cosmologie