English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Deviations from Gaussianity in the distribution of the fields probed bylarge-scale structure surveys generate additional terms in the data covariancematrix, increasing the uncertainties in the measurement of the cosmologicalparameters. Super-sample covariance (SSC) is among the largest of thesenon-Gaussian contributions, with the potential to significantly degradeconstraints on some of the parameters of the cosmological model under study --especially for weak lensing cosmic shear. We compute and validate the impact ofSSC on the forecast uncertainties on the cosmological parameters for the Euclidphotometric survey, obtained with a Fisher matrix analysis, both consideringthe Gaussian covariance alone and adding the SSC term -- computed through thepublic code PySSC. The photometric probes are considered in isolation andcombined in the `3$\times$2pt' analysis. We find the SSC impact to benon-negligible -- halving the Figure of Merit of the dark energy parameters($w_0$, $w_a$) in the 3$\times$2pt case and substantially increasing theuncertainties on $\Omega_{{\rm m},0}, w_0$, and $\sigma_8$ for cosmic shear;photometric galaxy clustering, on the other hand, is less affected due to thelower probe response. The relative impact of SSC does not show significantchanges under variations of the redshift binning scheme, while it is smallerfor weak lensing when marginalising over the multiplicative shear bias nuisanceparameters, which also leads to poorer constraints on the cosmologicalparameters. Finally, we explore how the use of prior information on the shearand galaxy bias changes the SSC impact. Improving shear bias priors does nothave a significant impact, while galaxy bias must be calibrated to sub-percentlevel to increase the Figure of Merit by the large amount needed to achieve thevalue when SSC is not included.

Euclid preparation. TBD. Forecast impact of super-sample covariance on 3x2pt analysis with Euclid