PhD Researcher (M/F) : Beyond the Flat Torus : Cosmological Explorations in Curved Spacetime

Job Description

Thesis Subject

As LSST and a new generation of major astronomical surveys prepare to map the Universe with unprecedented precision, cosmology continues to face persistent tensions. This improvement in measurement accuracy now requires observational uncertainties, theoretical systematics, and the approximations underlying cosmological models to be examined with the same level of scrutiny. Yet, despite the growing sophistication of the cosmological simulations used to interpret observational data, their geometric framework most often remains simple: a curvature-free periodic domain, assimilable to a flat torus. This PhD project aims to move beyond this limitation by enabling the numerical study of structure formation in universes with non-zero curvature or non-trivial topology. Working at the intersection of physics, mathematics, and computer science, the goal will be to overcome the scientific challenges that currently prevent such simulations: representing spaces numerically, defining boundary conditions, discretizing the equations of gravitation and matter dynamics, computing observables, and validating results in settings where the usual symmetries of the flat torus are no longer available. The objective will then be to study how the global geometry of the Universe can influence the formation of large-scale structures and leave an imprint on cosmological observables. Finally, access to the first LSST data will make it possible to connect these developments with observational analyses, in order to quantify these signatures and assess their detectability.

Qualification:

Hold a Master's degree or be in the process of obtaining one.

Skill:

Ability to present work in English (C2 level).

Personal Qualities:

Passion for research and experimental physics.
Ability to work in a team

Your Work Environment

LAPP is a laboratory of the Institute of Nuclear Physics and Particle Physics (IN2P3), an institute of the National Center for Scientific Research (CNRS), which coordinates programs in these fields. LAPP is a joint research unit (UMR 5814) of the CNRS and the University of Savoie Mont-Blanc (USMB). More than 150 researchers, teacher-researchers, engineers, technicians, administrators, students and foreign visitors work there. The research carried out at LAPP aims to study the physics of elementary particles and their fundamental interactions, as well as to explore their links with the great structures of the Universe. The work of the LAPP teams aims, among other things, to understand the origin of the mass of particles, to unravel the mystery of dark matter or to determine what happened to the anti-matter present in our universe at the time of the Big Bang.

The PhD candidate will join the cosmology/LSST team at LAPP, which is involved in the preparation and scientific exploitation of data from the cosmological survey conducted by the Vera C. Rubin Observatory. The recruited candidate will benefit from a highly interdisciplinary scientific environment, bringing together theoretical, numerical, observational, and instrumental expertise. They will work in close collaboration with team members involved in relativistic raytracing, which aims to better understand the effects of general relativity on observables related to gravitational lensing. More broadly, this project is part of a wider effort to contribute to the emergence of relativistic numerical cosmology.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions