Cosmological forecasts with the clustering of weak lensing peaks
Abstract
Maximizing the information that can be extracted from weak lensing (WL) measurements is a key goal for upcoming stage IV surveys. This is typically achieved through statistics that are complementary to the cosmic shear twopoint correlation function, the most well established of which is the WL peak abundance. In this work, we study the clustering of WL peaks, and present parameter constraint forecasts for an LSSTlike survey. We use the cosmoSLICS wCDM simulations to measure the peak twopoint correlation function for a range of cosmological parameters, and use the simulation data to train a Gaussian process regression emulator that is applied to generate likelihood contours and provide parameter constraint forecasts from mock observations. We investigate the dependence of the peak twopoint correlation function on the peak height, and find that the clustering of lowamplitude peaks is complementary to that of highamplitude peaks. Consequently, their combination gives significantly tighter constraints than the clustering of high peaks alone. The peak twopoint correlation function is significantly more sensitive to the cosmological parameters h and w_{0} than the peak abundance, and when the probes are combined, constraints on Ω_{m}, S_{8}, h, and w_{0} improve by at least a factor of 2, relative to the peak abundance alone. Finally, we compare the forecasts for WL peaks and voids, and show that the two are also complementary; both probes can offer better constraints on S_{8} and w_{0} than the shear correlation function by roughly a factor of 2.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 July 2022
 DOI:
 10.1093/mnras/stac1204
 arXiv:
 arXiv:2110.10164
 Bibcode:
 2022MNRAS.513.4729D
 Keywords:

 gravitational lensing: weak;
 methods: data analysis;
 cosmology: theory;
 largescale structure of universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 13 pages, 8 figures, comments welcome. arXiv admin note: text overlap with arXiv:2010.11954