SyncMoments

Documentation: https://syncmoments.readthedocs.io. Releases: https://github.com/zzhang0123/syncmoments/releases.

Differentiable JAX/Equinox synchrotron kernels, finite statistical contractions, and polarised radiative transfer for A statistical framework for synchrotron emission (Zhang & Chluba).

This research implementation keeps four operations explicit: physical kernel approximation, finite kernel Taylor expansion, statistical closure, and numerical solution. Passing a kernel or regression test does not certify a Galactic foreground model at 21-cm precision. All relevant discrepancies and uncertainties must be propagated to the chosen scientific quantity.

The positive finite-cumulant PDF reconstruction and the independent 21-cm assessment live in the manuscript repository’s validation/ directory. They do not import this package. CumulantExpansion here is the historical name of a quadratic kernel average; it is not that PDF reconstruction.

The main paper covers radiation kernels, population averages, moment/cumulant representations and their error control, including internally mixed emission and pure Faraday rotation. External screens are a special case. General ordered transfer, Magnus, absorption/conversion and the 21-cm examples remain exploratory modules beyond this main model.