Joint 2nd- and 3rd-order cosmic shear analysis on KiDS-Legacy data produces Ω_m = 0.297^{+0.056}_{-0.040} and S_8 = 0.806^{+0.025}_{-0.023}, consistent with Planck and prior KiDS results while improving Ω_m precision.
Euclid preparation: LXXXVII. Non-Gaussianity of 2-point statistics likelihood: Precise analysis of the matter power spectrum distribution
3 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
We investigate the non-Gaussian features in the distribution of the matter power spectrum multipoles. Using the COVMOS method, we generate 100\,000 mock realisations of dark matter density fields in both real and redshift space across multiple redshifts and cosmological models. We derive an analytical framework linking the non-Gaussianity of the power spectrum distribution to higher-order statistics of the density field, including the trispectrum and pentaspectrum. We explore the effect of redshift-space distortions, the geometry of the survey, the Fourier binning, the integral constraint, and the shot noise on the skewness of the distribution of the power spectrum measurements. Our results demonstrate that the likelihood of the estimated matter power spectrum deviates significantly from a Gaussian assumption on nonlinear scales, particularly at low redshift. This departure is primarily driven by the pentaspectrum contribution, which dominates over the trispectrum at intermediate scales. We also examine the impact of the finiteness of the survey geometry in the context of the Euclid mission and find that both the shape of the survey and the integral constraint amplify the skewness.
fields
astro-ph.CO 3years
2026 3representative citing papers
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KiDS-Legacy: Joint analysis of second- and third-order cosmic shear
Joint 2nd- and 3rd-order cosmic shear analysis on KiDS-Legacy data produces Ω_m = 0.297^{+0.056}_{-0.040} and S_8 = 0.806^{+0.025}_{-0.023}, consistent with Planck and prior KiDS results while improving Ω_m precision.
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\textit{Euclid} preparation. Baryon acoustic oscillations extraction techniques: comparison and optimisation
End-to-end validation on Euclid-like mocks shows RecSym and RecIso reconstruction yield unbiased BAO measurements, improving figure of merit for Omega_m and H0 rs by factor of ~3 across 0.9<z<1.8.
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Euclid preparation. Three-dimensional galaxy clustering in configuration space: Three-point correlation function estimation
Euclid collaboration develops and validates direct and spherical-harmonic estimators plus a random-split optimization for measuring the three-point galaxy correlation function at the scale of the full Euclid survey.