lemaitre.initial_data (LM-initial-data)

The initial-data domain of the Lemaitre package family: certified, differentiable, parametric binary-black-hole initial data.

This repository is the umbrella. It owns the lemaitre.initial_data namespace level and ships no science — the models live in the two submodules below, each its own repository and its own installable distribution.

import lemaitre as lm

lm.initial_data.conformally_flat_puncture    # the published Bowen–York puncture model
lm.initial_data.curved_puncture              # its non-conformally-flat successor

The two puncture models

conformally_flat_puncture — LMID-conformally-flat-puncture

Distribution LMID-conformally-flat-puncture. The paper package.

Certified, differentiable, parametric reduced-order model of the constraint solve for quasi-circular Bowen–York punctures, up to the 8-D general-spin model θ₈ = (b, q, χ_A, χ_B): a spectral xCFC solver on the Ansorg–Brügmann–Tichy prolate chart, matrix-free Newton–Krylov, and a Smolyak/Hermite/POD parameter-space ROM exposing solve(θ, guess) and the tangent dU/dθ. Ships paper/ — the code and the paper together.

curved_puncture — LMID-curved-puncture

Distribution LMID-curved-puncture. Skeleton — no physics yet.

The non-conformally-flat successor: the same ABT chart, the same Newton–Krylov solver, and the same parametric layer, with the conformally flat background replaced by an attenuated superposition of quasi-isotropic conformally-Kerr and Lorentz-boosted-Schwarzschild 3-metrics. The motivation is spin: above χ ≈ 0.93 conformally flat data does not exist at all, which is the published model's own stated limitation. It reuses conformally_flat_puncture directly — the chart, the Newton–Krylov solver and the ROM — and so depends on it.

Install

E="--config-settings editable_mode=compat"
pip install -e . $E                                  # this umbrella (pulls `lemaitre`)
pip install -e LMID-conformally-flat-puncture $E     # the published model
pip install -e LMID-curved-puncture $E               # the successor skeleton

python -c "import lemaitre as lm; lm.initial_data.conformally_flat_puncture"

The umbrella depends only on the lemaitre core. The solver stack (jax, numpy, scipy, matplotlib) comes with whichever model you install; both are self-contained beyond it, enforced by a test guard.

Each submodule builds, tests and releases on its own — see its README.md for the acceptance suite and, for conformally_flat_puncture, the paper-reproduction targets.

License

GPL-3.0 (see LICENSE).