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SHINE (SHear INference Environment) is a JAX-powered framework for probabilistic weak gravitational lensing shear estimation — a core measurement in cosmology used to study dark matter and dark energy.
The Core Problem
When light from distant galaxies passes near massive objects (galaxy clusters, dark matter halos), it gets deflected, causing the galaxy images to appear slightly distorted. Measuring this gravitational shear (the subtle stretching/rotation of galaxy shapes) lets astronomers map the distribution of matter in the universe.
Traditional approaches measure galaxy ellipticities and apply statistical corrections for instrumental effects. SHINE takes a fundamentally different, more principled approach.
SHINE's Approach: Bayesian Forward Modeling
Instead of measuring and correcting, SHINE:
Builds a generative forward model of the sky: renders galaxy images (Sersic profiles) via JAX-GalSim, convolves them with the telescope PSF, adds noise
Compares the forward model to observed pixel data to evaluate a likelihood
Runs Bayesian inference (MAP optimization or full MCMC/NUTS via NumPyro) to recover the posterior distribution of shear parameters
This treats shear measurement as a proper Bayesian inverse problem, avoiding the multiplicative/additive bias corrections that plague traditional methods.
Technology Stack
Component
Role
JAX
JIT compilation, autodiff, GPU support
NumPyro
Probabilistic programming, NUTS/HMC sampling
JAX-GalSim
Differentiable galaxy rendering & PSF convolution
Pydantic
YAML config validation
Current Status
The first instrument backend is shine.euclid — a full pipeline for Euclid VIS multi-exposure data:
Reads quadrant FITS files, PSF grids, and MER source catalogs
Filters sources by SNR, quality flags, and size
Renders scenes with spatially-varying PSFs across multiple exposures
The project is in early/alpha development from the CosmoStat Lab (CEA/CNRS), with plans to extend to LSST, MeerKAT, and non-parametric galaxy morphology models.
Activity
EiffL commentedon Feb 24, 2026
@claude can you tell me what this repo does
claude commentedon Feb 24, 2026
Claude finished @EiffL's task in 41s —— View job
What SHINE Does
SHINE (SHear INference Environment) is a JAX-powered framework for probabilistic weak gravitational lensing shear estimation — a core measurement in cosmology used to study dark matter and dark energy.
The Core Problem
When light from distant galaxies passes near massive objects (galaxy clusters, dark matter halos), it gets deflected, causing the galaxy images to appear slightly distorted. Measuring this gravitational shear (the subtle stretching/rotation of galaxy shapes) lets astronomers map the distribution of matter in the universe.
Traditional approaches measure galaxy ellipticities and apply statistical corrections for instrumental effects. SHINE takes a fundamentally different, more principled approach.
SHINE's Approach: Bayesian Forward Modeling
Instead of measuring and correcting, SHINE:
This treats shear measurement as a proper Bayesian inverse problem, avoiding the multiplicative/additive bias corrections that plague traditional methods.
Technology Stack
Current Status
The first instrument backend is
shine.euclid— a full pipeline for Euclid VIS multi-exposure data:(g1, g2)+ per-source morphology parametersThe project is in early/alpha development from the CosmoStat Lab (CEA/CNRS), with plans to extend to LSST, MeerKAT, and non-parametric galaxy morphology models.