Observational cosmologist, specialised in instrument modeling, systematic studies and data analysis for Cosmic Microwave Background (CMB) polarisation experiments.
I am a staff scientist in the
CMB group
at Berkeley Lab.
I completed my PhD at APC in Paris in 2020, and was then
a Harvard Postdoctoral Fellow at the Center for Astrophysics
within the CMB group until 2024.
I am a member of the BICEP/Keck and CMB-S4 collaborations.
If you are a UC Berkeley Physics or Astronomy undergraduate or graduate student, or a prospective post-doc, and are interested in CMB science
at Berkeley Lab, reach out!
Selfie with the POLARBEAR-2a telescope during its commissioning in Chile, in November 2019
My research work focuses on studying the signal of the CMB to look for a specific polarisation pattern: the cosmological B-modes. The detection of this signal would be a smoking gun for inflation theories, allowing us to better understand the very beginning of the Universe.
I focus on calibration and systematics in the context of multi-component data anaylsis. I develop advanced data analysis techniques to precisely estimate the impact of instrumental systematics on our science results, and how to mitigate their impact in various ways. I also actively participate in design, integration and calibration of current and future receivers.
Understanding instrumental systematics require high precision calibration data, as these measurements are an essential step to ensure that instrumental effects are properly taken into account in the analysis. I work first-hand on calibration campaign for CMB telescopes, to make sure we have all necessary measurements to understand the performance of our instruments.
I work on estimating the impact of various instrumental effects on science results, in particular on cosmological parameters of interest in the search for inflation. I develop frameworks to analyse calibration data and tie them to cosmological analysis. This work also informs calibration campaigns, so that we know the precision of the measurement we need to properly constraint instrumental effects.
One of the main challenges in our quest for B-modes is to be able to separate the CMB signal from Galactic contaminations. This step, known as component separation, requires accurate models of both the instrument and Galactic emission. I develop component separation methods that take into account the interplay between instrumental characteristics and foreground complexity.
Cosmic birefringence is an elusive manifestation of parity violation in the electromagnetic interaction. It would manifest as a rotation of CMB polarisation as the signal travels through our Universe. The amplitude of this effect is very low, and degenerate with instrumental polarisation. Constraining it is therefore an instrumental and data analysis challenge. With my BK colleague Dr. James Cornelison, we have been leading the effort in the BK collaboration to extract birefringence constraints from our CMB data. We have recently published our findings in a BICEP/Keck collaboration paper: Measurement of BICEP3 polarization angles and consequences for constraining cosmic birefringence and inflation... and there is more to come!
I love sharing my passion for cosmology outside the lab! I regularly engage in outreach activities,
most recently with the CMB-S4 Education & Public Outreach program
and UC Berkeley Astro Night.
You can also find me on Skype a Scientist.
In the past, I had the chance to be part of Fête le Savoir,
Universciel
and SpaceUp France, and organise many wonderful events with them.
Whether the focus is space or cosmology, I always enjoy planning and hosting events, packed with conferences
and hands-on activities!
Left: Harvard Astro 191 field trip to the Holmdel Horn Antenna with Dr. Robert Wilson, who discovered the CMB using the antenna in 1965. Right: Group photo during the Astrojeunes summer camp
UC Berkeley Astro Night public talk in March 2025, with my LBNL colleagues Dr. John Groh and Julien Tang