Metadata-Version: 2.4
Name: implosive-backreaction-utac
Version: 0.1.0
Summary: Cosmological backreaction (Buchert averaging, viscous cosmology) as a testable, falsifiable mechanism for late-time acceleration without fundamental dark energy
Author: Römer, Johann
License: MIT
License-File: LICENSE
Requires-Python: >=3.11
Provides-Extra: dev
Requires-Dist: mypy>=1.10.0; extra == 'dev'
Requires-Dist: pre-commit>=3.7.0; extra == 'dev'
Requires-Dist: pytest-cov>=5.0.0; extra == 'dev'
Requires-Dist: pytest>=8.0.0; extra == 'dev'
Requires-Dist: ruff>=0.6.0; extra == 'dev'
Description-Content-Type: text/markdown

# implosive-backreaction-utac

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GenesisAeon Package 98 — cosmological backreaction as a falsifiable
mechanism for late-time acceleration without fundamental dark energy.
**Distinct from `implosive-genesis` (P73) and `implosive-origin-utac`
(P33)** — see [DISCLAIMER.md](DISCLAIMER.md).

## What's real here

- Buchert (2000, *General Relativity and Gravitation*): the averaged
  Einstein equations for irrotational dust, and the kinematical
  backreaction term Q_D = variance(expansion) − 2·shear².
- Raesaenen (2004, *JCAP*): the wall/void two-region toy model this
  package implements as `wall_void_backreaction()`.
- Wiltshire (2007, *PRL*): Timescape cosmology, the exact two-scale
  Buchert average this package's `BuchertScalingModel` is consistent
  with.
- Israel & Stewart (1979, *Annals of Physics*): the causal theory
  behind the effective-viscosity mechanism (`ViscousBackreaction`).
- A proven **No-Go** for the naive reading ("distributed matter alone
  accelerates the universe") — deliberately included, see
  [DISCLAIMER.md](DISCLAIMER.md) for why this doesn't refute the actual
  mechanism.
- Green & Wald's (2011) counter-position — that small-scale
  inhomogeneities don't produce relevant backreaction — represented
  honestly as an open dispute, not omitted.

## Quickstart

```bash
pip install implosive-backreaction-utac
```

```python
from implosive_backreaction_utac import (
    naive_hypothesis_accelerates,   # the No-Go: False for realistic G_eff(a)
    wall_void_backreaction,         # Q_D from regional expansion-rate variance
    BuchertScalingModel,            # power-law closure, w_X, transition redshift
    ViscousBackreaction,            # closed-form H(a), q(a) -> -1 at late times
    compare_models,                 # q(a)/w_eff(a) side by side vs LambdaCDM
)

print(naive_hypothesis_accelerates(s=0.2))  # False -- the naive reading fails

q_d = wall_void_backreaction(f_v=0.8, h_v=1.4, h_w=0.6)
model = BuchertScalingModel(q0=q_d, n=-0.5)
print(model.w_x)  # -5/6: a dynamical, accelerating effective fluid

viscous = ViscousBackreaction(zeta=0.05, g_newton=1.0, h0=1.0)
print(viscous.q(a=100.0))  # approaches -1: late-time acceleration
```

## Development

```bash
pip install -e ".[dev]"
pre-commit install
ruff check src tests
mypy src
pytest
```

## Citation

See [CITATION.cff](CITATION.cff) and [.zenodo.json](.zenodo.json).
