Simulating Partial Sky Cosmic Microwave Background Maps with 3D Fast Fourier Transforms
Fuente:
arXiv
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866913951257722880 |
|---|---|
| author | Mascarell, Mariona Giner Bunn, Emory F. |
| author_facet | Mascarell, Mariona Giner Bunn, Emory F. |
| contents | Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the use of fast Fourier transforms (FFTs). Current and near-future experiments, particularly ones like CMB S4, will cover areas too large for the flat-sky approximation but significantly less than the full sky. In this regime, it can be more efficient to simulate maps in a 3-D box using FFTs, and then sample onto the observed part of the celestial sphere. We present a method for performing such simulations and show that it can be more efficient than full-sky simulations. We develop the method for scalar maps, but we expect it to be applicable to higher-spin (e.g., polarization) simulations as well. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_15703 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Simulating Partial Sky Cosmic Microwave Background Maps with 3D Fast Fourier Transforms Mascarell, Mariona Giner Bunn, Emory F. Cosmology and Nongalactic Astrophysics Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the use of fast Fourier transforms (FFTs). Current and near-future experiments, particularly ones like CMB S4, will cover areas too large for the flat-sky approximation but significantly less than the full sky. In this regime, it can be more efficient to simulate maps in a 3-D box using FFTs, and then sample onto the observed part of the celestial sphere. We present a method for performing such simulations and show that it can be more efficient than full-sky simulations. We develop the method for scalar maps, but we expect it to be applicable to higher-spin (e.g., polarization) simulations as well. |
| title | Simulating Partial Sky Cosmic Microwave Background Maps with 3D Fast Fourier Transforms |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2507.15703 |