UFalcon (Ultra Fast Lightcone)

Package for constructing signal maps for multiple cosmological probes given N-Body code output. Written in Python3.

Source

Documentation

Why use UFalcon?

UFalcon is a tool for rapidly post-processing N-body code output into signal maps for many different cosmological probes. The package is able to produce maps of weak-lensing convergence, linear-bias galaxy overdenisty, cosmic micowave background (CMB) lensing convergence and the integrated Sachs-Wolfe temperature perturbation given a set of N-body lightcones. The output of the code for the above signals has been tested against analytical theoretical predictions to a high degree of accuracy in Reeves et al. 2023. The package offers a high flexibility for the lightcone construction, such as user-specific survey- redshift ranges, redshift distributions and single-source redshifts. UFalcon also offers the possibility to compute the galaxy intrinsic alignment signal, which can be treated as an additive component to the cosmological signal.

Features

• Fast construction of probe maps for user-specific redshift distributions and single-source redshifts including weak lensing convergence, galaxy clustering (linear bias model), CMB lensing and CMB ISW signals computed on the lightcone used in Reeves et al. 2023
• Computation of galaxy intrinsic alignment (IA) signal (additive to the cosmological signal) based on the nonlinear intrinsic alignment model (NLA) (Bridle et al. 2007, Hirata et al. 2004 and Joachimi et al. 2011) and applied in Zürcher et al. 2020.

Basic usage

• See the example demo_notebook (found in the notebooks folder of the repo or the Usage section of the docs) which demonstrates using UFalcon on a small test set of lightcone output.

N-Body Simulations

UFalcon is able to post-process any set of lightcone shells produced by an N-body code into cosmological signal maps, though we recommend the cosmogrid suite of simualtions (Kacprzak et al. 2022) available here, which can be easily interfaced with UFalcon. Note that UFalcon currently only supports post-processing of simulation output generated in lightcone mode.

Development

If you are working on this repo, follow these recommendations:

• Clone the repo, cd into the directory, and install the package with python -m pip install -e .. The e flag allows you to make changes to the code and have such changes reflected in your import of UFalcon, without the need to reinstall the package every time.
• To test any updates in documentation using Sphinx, follow these steps:
  • Install the package with the e flag, per above
  • Install sphinx_rtd_theme via pip install sphinx_rtd_theme
  • Run make docs
  • Check the output HTML files in docs/_build/ folder

Credits

Introduced in Sgier et al. 2019, Sgier et al. 2020 and extended in Reeves et al. 2023.

• If you use UFalcon for your research please cite Reeves et al. 2023, Sgier et al. 2019 and Sgier et al. 2020.
• Copyright (C) 2023 ETH Zurich, Institute for Particle Physics and Astrophysics, Cosmology Group
• Contact: Alexander Reeves areeves@phys.ethz.ch.