Postdoctoral position in probabilistic modelling and analysis for cosmology (M/F)

Job Description

Missions

Contribute to the AstroDeep² project, led jointly by the APC (Université Paris Cité) and CosmoStat at CEA Paris-Saclay, with a view to developing new probabilistic modelling and analysis methods for the optimal exploitation of large astronomical surveys such as Euclid and Rubin/LSST. To help address the major systematic effects in next-generation imaging surveys, including blending issues, the estimation of photo-z and galactic shapes, and the rigorous propagation of uncertainties into the final cosmological inference.

Activity

- To develop and evaluate multimodal architectures combining imaging and spectroscopy for deblending, photo-z estimation and robust measurement of galactic properties.
- Construct probabilistic galaxy catalogues and incorporate these outputs into Bayesian shear measurement chains in order to propagate uncertainties through to the cosmological results.
- Help supervise PhD students working on these topics.
- Depending on the candidate profile, contribute to the curation of datasets, the assessment of model generalisation, the calibration of uncertainties, and the software integration of the project's various modules.

Your Profil

Skills

- PhD, or due to defend shortly, in astrophysics, cosmology, statistics, machine learning or a related field.
- A strong command of at least one of the following fields: differentiable simulations, accelerated physical modelling, astronomical image processing, weak lensing, deblending, Bayesian inference, simulation-based inference or probabilistic deep learning.
- Experience with frameworks such as JAX, PyTorch or TensorFlow, as well as with simulation or image analysis tools such as GalSim, would be an advantage.
- Strong skills in Python programming and collaborative development (Git/GitHub, CI/CD, open-source practices).
- Ability to conduct research independently whilst contributing effectively to an interdisciplinary team.
- Excellent ability to communicate scientific information in English, both in writing and orally.
- Experience in major astronomical collaborations, such as Euclid or LSST, is an advantage but not essential.

Your Work Environment

The AstroDeep² project aims to harness the full informational content of large Phase IV imaging surveys by developing a unified, probabilistic and differentiable framework for cosmological analysis. A postdoctoral position is available at the APC in Paris, within a dynamic research environment at the interface between cosmology, statistics and data science. The AstroDeep team at the APC is based in the heart of Paris and is heavily involved in international collaborations such as Euclid and the LSST DESC.
The project and the laboratory promote a collaborative, inclusive and work-life-balance-friendly working environment, offering benefits such as comprehensive health insurance, holiday leave, subsidised meals, travel discounts and optional French lessons.

Compensation and benefits

Compensation

Between 3132.83€ and 3571.35€ gross per month depending on the experience

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

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