CosmoBLENDER

Cosmological Biases to LENsing and Delensing Due to Extragalactic Radiation

CosmoBLENDER computes foreground-induced biases to temperature-based CMB lensing reconstructions, including:

• CMB lensing auto-correlations,
• CMB lensing cross-correlations with galaxies,
• internal B-mode delensing.

The implementation follows Baleato Lizancos et al. 2025.

Installation

Install from PyPI with:

 python -m pip install cosmoblender

Optional FFTlog functionality requires pyccl:

 python -m pip install "cosmoblender[fftlog]"

Core dependencies

• NumPy, SciPy, Matplotlib
• BasicILC from this fork
• Hmvec from its galaxy branch for CIB calculations
• Quicklens (Python 3 version)
• astropy

Usage

Tutorial notebooks live in notebooks/ in the GitHub repository.

Start with notebooks/example_pipeline.ipynb, then see:

• notebooks/auto_correlations.ipynb
• notebooks/cross_correlations.ipynb
• notebooks/delensing.ipynb

Attribution

If you use the code, please cite Baleato Lizancos et al. 2025.