BAR_IMPACT

A Python package for analyzing the impact of baryonic physics on cosmological weak lensing maps using simulation-based inference.

Overview

BAR_IMPACT provides tools for:

• Summary Statistics: L1 norms (wavelet coefficients), angular power spectra, peak counts
• Tomographic Analysis: BNT (Bernardeau-Nishimichi-Taruya) transform for nulling redshift correlations
• Simulation-Based Inference: Neural Posterior Estimation (NPE) with JAX
• Posterior Validation: TARP coverage testing

Installation

# Basic installation
pip install -e .

# With inference dependencies (JAX, jaxili)
pip install -e ".[inference]"

# With development tools
pip install -e ".[dev]"

# All dependencies
pip install -e ".[all]"

External Dependencies

• pycs - Required for wavelet L1 norms and peak counts
• jaxili - Required for NPE inference

Quick Start

from bar_impact.core import ConvergenceMap, SurveyMask
from bar_impact.processing import PowerSpectrumProcessor

# Load convergence map
kappa = ConvergenceMap.from_h5("simulation.h5", bin_number=1)

# Add shape noise and apply survey mask
kappa = kappa.add_shape_noise(sigma_e=0.26)
mask = SurveyMask.create_disk_mask(nside=512, target_area_sqdeg=14000)
kappa = kappa.apply_mask(mask)

# Compute power spectrum
processor = PowerSpectrumProcessor(lmax=1024)
cls = processor.process_single(kappa.data)

Package Structure

src/bar_impact/
├── core/           # ConvergenceMap, SurveyMask, DataVector
├── processing/     # L1NormProcessor, PowerSpectrumProcessor, PeakCountProcessor
├── inference/      # NPEInference, CoverageTester
├── analysis/       # Aggregation and visualization
├── utils/          # I/O, noise generation, reproducibility
└── constants.py    # BNT matrices, default parameters

Documentation

Full documentation is available at bar-impact.readthedocs.io

• Installation Guide
• Quick Start Tutorial
• API Reference

Testing

pytest tests/ -v

License

MIT License - see LICENSE for details.

Citation

If you use this package, please cite:

@software{bar_impact,
  author = {Tersenov, Andreas},
  title = {BAR_IMPACT: Baryon Impact Analysis for Weak Lensing},
  url = {https://github.com/AndreasTersenov/bar_impact}
}