Towards an Era of Precision Cosmology: the COSMOcal Project

Observations of the Cosmic Microwave Background (CMB) have transformed cosmology into a high-precision science. Today, the detection of the imprint of primordial gravitational waves on the CMB polarization signal (the so-called primordial B-modes) is the foremost challenge of ground-based experiments and the LiteBIRD space mission. To match the sensitivity of these future experiments, we need to improve the detection accuracy by several orders of magnitude both experimentally and in data analysis.

This seminar aims to provide an overview of the CMB as a unique probe of the early Universe and to illustrate the scientific motivations and technological challenges of the current generation of CMB experiments under development.
In this context, I am leading the COSMOCal project, so far funded by the PSL University in Paris, whose goal is to provide a solution to a critical aspect of the calibration of polarization instruments, which could prevent us from an unbiased detection of the primordial B-modes. Particular attention will be paid to making the seminar as accessible as possible to a non-expert audience.

Brief CV of Dr. Alessia Ritacco:
Alessia Ritacco graduated from La Sapienza University in 2012 with a thesis in experimental cosmology under the supervision of Prof. Paolo de Bernardis.
In 2016, she completed her PhD funded by CNES at the LPSC laboratory (Grenoble, FR), focused on the development and observations of the polarization system of the NIKA2 camera (aka NIKA2pol). She then worked at the IRAM institute in Granada on the scientific commissioning of NIKA2pol, also serving as an astronomer on duty for the IRAM 30m telescope. In 2019, she moved to Paris and worked at the IAS institute (Orsay) and the Ecole Normale Superieure (Paris) on the latest polarization data from the Planck satellite. Since 2021, she has been a post-doc working on the SRT upgrade. From February 2024, she will join the cosmology group at the University of Tor Vergata in Rome, where she will work on the next generation of cosmology experiments.