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: Optimising tomographic redshift binning for 3$\times$2pt power spectrum constraints on dark energy
5 Pith papers cite this work. Polarity classification is still indexing.
5
Pith papers citing it
abstract
We present a simulation-based method to explore the optimum tomographic redshift binning strategy for 3x2pt analyses with Euclid, focusing on the expected configuration of its first major data release (DR1). To do this, we 1) simulate a Euclid-like observation and generate mock shear catalogues from multiple realisations of the 3x2pt fields on the sky, and 2) measure the 3x2pt Pseudo-Cl power spectra for a given tomographic configuration and derive the constraints that they place on the standard dark energy equation of state parameters (w0, wa). For a simulation including Gaussian-distributed photometric redshift uncertainty and shape noise under a LambdaCDM cosmology, we find that bins equipopulated with galaxies yield the best constraints on (w0, wa) for an analysis of the full 3x2pt signal, or the angular clustering component only. For the cosmic shear component, the optimum (w0, wa) constraints are achieved by bins equally spaced in fiducial comoving distance. However, the advantage with respect to alternative binning choices is only a few percent in the size of the $1\,\sigma\,$(w0, wa) contour, and we conclude that the cosmic shear is relatively insensitive to the binning methodology. We find that the information gain extracted on (w0, wa) for any 3x2pt component starts to saturate at $\gtrsim$ 7-8 bins. Any marginal gains resulting from a greater number of bins is likely to be limited by additional uncertainties present in a real measurement, and the increasing demand for accuracy of the covariance matrix. Finally, we consider a 5% contamination from catastrophic photometric redshift outliers and find that, if these errors are not mitigated in the analysis, the bias induced in the 3x2pt signal for 10 equipopulated bins results in dark energy constraints that are inconsistent with the fiducial LambdaCDM cosmology at $>5\,\sigma$.
representative 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.
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.
Einstein-Cartan cosmology predicts much larger mass density and sigma_8(z) at high redshifts than LCDM, making the S8 discrepancy between CMB and low-redshift data a natural outcome rather than a problem.
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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\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.
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Einstein-Cartan cosmology and the S8 problem
Einstein-Cartan cosmology predicts much larger mass density and sigma_8(z) at high redshifts than LCDM, making the S8 discrepancy between CMB and low-redshift data a natural outcome rather than a problem.