About me
I am Pierre Boccard, a PhD student in observational cosmology at the Centre de Physique des Particules de Marseille (CPPM, CNRS / IN2P3), within Aix-Marseille Université. I work under the supervision of Prof. Alice Pisani on the imprint of photometric-redshift systematics on the cosmic void abundance, as part of the Vera C. Rubin Observatory / LSST collaboration.
My PhD is titled "Study of systematic effects of photometric redshifts on the Void Size Function". Cosmic voids — the vast, underdense regions of the universe — are exquisite cosmological probes, but the noisy distance estimates of photometric surveys distort their statistics. My work aims to characterise these biases and to build calibration strategies that let Rubin/LSST exploit voids as a competitive dark-energy and modified-gravity probe.
Before joining CPPM, I obtained a Master in Astrophysics at the Swiss Federal Institute of Technology (EPFL). I carried out my Master Thesis at the University of Chicago with Prof. Joshua Frieman and Dr. Anowar Shajib, measuring the dark-energy equation of state from the compound strong-lens system DES J0408−5354 with Lenstronomy. Earlier I worked at LASTRO (EPFL) with Jean-Paul Kneib and Andrei Variu on the void–galaxy cross-correlation as a redshift-space-distortion probe.
I was raised in France by a Croatian mother and a French father — both scientists — and grew up between French, Croatian and English. Outside the lab I shoot 35 mm film, play music, and chase long-distance running goals along the calanques of Marseille.
My GitHub is PierreBoccard.
Research interests
- Cosmic voids, void size function, void–galaxy cross-correlation
- Photometric redshifts and survey systematics
- Vera C. Rubin Observatory / LSST, DES, Euclid
- Large-scale structure, dark energy, modified gravity
- N-body simulations and mock-catalogue pipelines
Technical toolbox
- Python (NumPy, SciPy, Astropy, healpy, JAX), C / C++, Fortran
- Void finders (VIDE / ZOBOV, Voronoi-Voids pipelines), N-body post-processing
- Statistical inference (MCMC, Fisher forecasts, emulators)
- HPC workflows on the CC-IN2P3 cluster
Résumé
The full PDF is here.