Venez assister à la retransmission du lancement en direct de la mission Euclid en compagnie des chercheurs et techniciens ayant contribué à la construction du satellite!
I'll talk about ongoing efforts to model optical non-idealities in CMB experiments, with a focus on generating simulated timestreams and maps. After introducing the concept of beam convolution, I'll discuss how we can model beams using optics software. I will then show a few examples of non-idealities we have been studying in Stockholm with collaborators by inserting these beams into various simulated experiments.
The new weak lensing measurements from the first three years of observation by the Dark Energy Survey offer a unique opportunity to constrain deviations from General Relativity, our theory of gravity. Weak gravitational lensing is indeed a powerful probe of the growth of structures. As such it offers a window on the laws of gravity on cosmological scales. We thus used DES Year 3 weak lensing data to test the validity of General Relativity (GR) to a new regime, and explore modifications to GR as an alternative to dark energy.
C’est avec plaisir que je vous invite à suivre ma soutenance de thèse, le jeudi 29 septembre à 11:00, à Condorcet, salle 646A.
Durant cette soutenance, je présenterai les travaux de ma thèse, intitulée "L’évolution des galaxies dans les amas et les groupes jusqu’à z~3 ", sous la direction de Simona Mei.
We are glad to announce that the second edition of a workshop on Bayesian Deep Learning for Cosmology and Time Domain Astrophysics 2022 is open for registration. It will be held in Paris, France the week of June 20th to 24th and a call for contributions is open until May 18th.
This talk will discuss synergies between the Nancy Grace Roman Space Telescope and CMB lensing data to constrain dark energy and modified gravity scenarios. We will present a simulated likelihood analysis of the galaxy clustering and weak lensing data from the Roman Space Telescope High Latitude Survey combined with CMB lensing data from the Simons Observatory, marginalizing over important astrophysical effects and calibration uncertainties.
Faint extended elliptically shaped ultra-diffuse galaxies and slightly brighter and more compact dwarf elliptical and lenticular stellar systems are common in galaxy clusters. Their poorly constrained evolutionary paths can be studied by identifying young ultra-diffuse galaxy and dwarf elliptical analogues populated with bright, massive stars. Using data mining we identified 11 such low-mass (2 × 10^8 M⊙ < M* < 2 × 10^9 M⊙) galaxies with large half-light radii (2.0 kpc < re < 5 kpc) and recently quenched star formation in the Coma and Abell 2147 galaxy clusters.
The ΛCDM Model accurately reproduces most cosmological observations, including primordial nucleosynthesis, the cosmic microwave background radiation, and baryonic acoustic oscillations. However, standard baryonic matter constitutes only 5% of the total content of the ΛCDM universe, while the dominant components – cold dark matter (≈25%) and dark energy (≈70%) – are yet unobserved.
