2015/07/31 by Robert Reischke, Matteo Maturi, M. Maturi +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Extreme value theory #Field galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Gravitational lens #Halo #Physics #Redshift #Redshift survey #Statistical physics #Statistics #Weak gravitational lensing #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stv2677
published as Monthly Notices of the Royal Astronomical Society 2016 456 (1): 641-653 · 14 pages, 11 figures, Accepted for publication in MNRAS, one figure added, little changes in the manuscript, added references
arxiv created 2015/11/12 · openalex publication_date 2015/12/16 · arxiv updated 2016/12/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The statistics of peaks in weak gravitational lensing maps is a promising technique to constrain cosmological parameters in present and future surveys. Here we investigate its power when using general extreme value statistics which is very sensitive to the exponential tail of the halo mass function. To this end, we use an analytic method to quantify the number of weak lensing peaks caused by galaxy clusters, large-scale structures and observational noise. Doing so, we further improve the method in the regime of high signal-to-noise ratios dominated by non-linear structures by accounting for the embedding of those counts into the surrounding shear caused by large-scale structures. We derive the extreme value and order statistics for both overdensities (positive peaks) and underdensities (negative peaks) and provide an optimized criterion to split a wide field survey into subfields in order to sample the distribution of extreme values such that the expected objects causing the largest signals are mostly due to galaxy clusters. We find good agreement of our model predictions with a ray-tracing N-body simulation. For a Euclid-like survey, we find tight constraints on σ8 and Ωm with relative uncertainties of ∼10−3. In contrast, the equation of state parameter w0 can be constrained only with a 10 per cent level, and wa is out of reach even if we include redshift information.