Fast modeling of the shear three-point correlation function
The three-point correlation function (3PCF) of a weak lensing shear field contains information that is complementary to that in the two-point correlation function (2PCF), which can help improve the cosmological parameters and calibrate astrophysical and observational systematics parameters. However,...
Saved in:
Main Authors | , , |
---|---|
Format | Journal Article |
Language | English |
Published |
01.07.2024
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The three-point correlation function (3PCF) of a weak lensing shear field
contains information that is complementary to that in the two-point correlation
function (2PCF), which can help improve the cosmological parameters and
calibrate astrophysical and observational systematics parameters. However, the
application of the 3PCF to observed data has been limited due to the
computational challenges of calculating theoretical predictions of the 3PCF
from a bispectrum model. In this paper, we present a new method to compute the
shear 3PCF efficiently and accurately. We employ the multipole expansion of the
bispectrum to compute the shear 3PCF, and show that the method is substantially
more efficient than direct numerical integration. We found that the
multipole-based method can compute the shear 3PCF with 5% accuracy in 10 (40)
seconds for the single (four) source redshift bin setup. The multipole-based
method can be also used to compute the third-order aperture mass statistics
quickly and accurately, accounting for the bin-averaging effect on the shear
3PCF. Our method provides a fast and robust tool for probing the underlying
cosmological model with third-order statistics of weak lensing shear. |
---|---|
DOI: | 10.48550/arxiv.2407.01798 |