KiDS-Legacy: Constraining dark energy, neutrino mass, and curvature
Authors
Robert Reischke
Benjamin Stölzner
Benjamin Joachimi
Angus H. Wright
Marika Asgari
Maciej Bilicki
Nora Elisa Chisari
Andrej Dvornik
Christos Georgiou
Benjamin Giblin
Joachim Harnois-Déraps
Catherine Heymans
Hendrik Hildebrandt
Henk Hoekstra
Shahab Joudaki
Konrad Kuijken
Shun-Sheng Li
Laila Linke
Arthur Loureiro
Constance Mahony
Lauro Moscardini
Lucas Porth
Mario Radovich
Tilman Tröster
Maximilian von Wietersheim-Kramsta
Ziang Yan
Mijin Yoon
Yun-Hao Zhang
Abstract
We constrain minimally extended cosmological models with the cosmic shear analysis of the final data release from the Kilo-Degree Survey (KiDS-Legacy) in combination with external probes. Due to the consistency of the KiDS-Legacy analysis with the Cosmic Microwave Background (CMB), we can combine these data sets reliably for the first time. Additionally, we use CMB lensing, galaxy redshift-space distortions, and baryon acoustic oscillations. We assess, in turn, the effects of spatial curvature, varying neutrino masses, and an evolving dark energy component on cosmological constraints from KiDS-Legacy alone and in combination with external probes. We find KiDS-Legacy to be consistent with the fiducial flat $Λ$CDM analysis with $c^2 \sum m_ν\leq 1.5\,$eV, $w_0 = -1.0\pm 0.7$ and $w_a = -1.3^{+1.9}_{-2.0}$ while $Ω_K = 0.08^{+0.16}_{-0.17}$ (1$σ$ bounds) with almost equal goodness-of-fit. $w_0w_a$CDM is not a significant improvement over $Λ$CDM when cosmic shear and CMB lensing are combined, yielding a Bayes factor $B = 0.07$. If all probes are combined, however, $B$ increases to 2.73, corresponding to a $2.6σ$ suspicousness tension. The constraint on $S_8 = σ_8\sqrt{Ω_\mathrm{m}/0.3}$ is robust to opening up the parameter space for cosmic shear. Adding all external datasets to KiDS-Legacy, we find with $S_8 = 0.816 \pm 0.006$ in $Λ$CDM and $S_8 = 0.837 \pm 0.008$ in $w_0 w_a$CDM for all probes combined.
