The authors derive the fourth-order galaxy-galaxy lensing 4PCF and aperture statistics, implement a numerical pipeline and FFT estimator, and detect the connected ⟨N³ M_ap⟩ signal at SNR ~9 in stage IV mock data over 2000 deg².
Euclid preparation: 6x2 pt analysis of Euclid's spectroscopic and photometric data sets
5 Pith papers cite this work. Polarity classification is still indexing.
abstract
We present cosmological parameter forecasts for the Euclid 6x2pt statistics, which include the galaxy clustering and weak lensing main probes together with previously neglected cross-covariance and cross-correlation signals between imaging/photometric and spectroscopic data. The aim is understanding the impact of such terms on the Euclid performance. We produce 6x2pt cosmological forecasts, considering two different techniques: the so-called harmonic and hybrid approaches, respectively. In the first, we treat all the different Euclid probes in the same way, i.e. we consider only angular 2pt-statistics for spectroscopic and photometric clustering, as well as for weak lensing, analysing all their possible cross-covariances and cross-correlations in the spherical harmonic domain. In the second, we do not account for negligible cross-covariances between the 3D and 2D data, but consider the combination of their cross-correlation with the auto-correlation signals. We find that both cross-covariances and cross-correlation signals, have a negligible impact on the cosmological parameter constraints and, therefore, on the Euclid performance. In the case of the hybrid approach, we attribute this result to the effect of the cross-correlation between weak lensing and photometric data, which is dominant with respect to other cross-correlation signals. In the case of the 2D harmonic approach, we attribute this result to two main theoretical limitations of the 2D projected statistics implemented in this work according to the analysis of official Euclid forecasts: the high shot noise and the limited redshift range of the spectroscopic sample, together with the loss of radial information from subleading terms such as redshift-space distortions and lensing magnification. Our analysis suggests that 2D and 3D Euclid data can be safely treated as independent, with a great saving in computational resources.
fields
astro-ph.CO 5representative citing papers
CosmoPostProcess delivers simulation-calibrated radial corrections for projection-induced selection bias (20-40% amplitude near 1 h^{-1} Mpc) and baryonic effects in Euclid richness-selected cluster weak lensing profiles.
CLOE pipeline produces forecasts showing Euclid can reach FoM >400 for dark energy w0 and wa by combining primary probes on synthetic data.
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.
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.
citing papers explorer
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Fourth-order galaxy-galaxy-lensing: Theoretical framework and direct estimation
The authors derive the fourth-order galaxy-galaxy lensing 4PCF and aperture statistics, implement a numerical pipeline and FFT estimator, and detect the connected ⟨N³ M_ap⟩ signal at SNR ~9 in stage IV mock data over 2000 deg².
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Euclid preparation. CosmoPostProcess: A simulation calibrated framework for weak lensing selection bias in richness-selected galaxy clusters
CosmoPostProcess delivers simulation-calibrated radial corrections for projection-induced selection bias (20-40% amplitude near 1 h^{-1} Mpc) and baryonic effects in Euclid richness-selected cluster weak lensing profiles.
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Euclid preparation. XCVI. Cosmology Likelihood for Observables in Euclid (CLOE). 3. Inference and Forecasts
CLOE pipeline produces forecasts showing Euclid can reach FoM >400 for dark energy w0 and wa by combining primary probes on synthetic data.
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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.