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, Shangrong Li, Laila Linke, A. Loureiro, Constance Mahony, L. Moscardini, N. R. Napolitano, Lucas Porth, M. Radovich, Tilman Tröster, Maximilian von Wietersheim-Kramsta, Ziang Yan, Yoon MS, Yun-Hao Zhang
We constrained 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 could combine these datasets reliably for the first time. Additionally, we used CMB lensing, galaxy redshift-space distortions, and baryon acoustic oscillations. We assessed, in turn, the effects of spatial curvature, varying neutrino masses, and an evolving dark energy component on cosmological constraints from KiDS-Legacy alone and from KiDS-Legacy combined with external probes. We find KiDS-Legacy to be consistent with the fiducial flat Λ-cold dark matter (ΛCDM) analysis with c 2 ∑ m ν ≤ 1.5 eV, w 0 = −1.0 ± 0.7, and w a = −1.3 −2.0 +1.9 while Ω K = 0.8 −0.17 +0.16 (1 σ bounds) with an almost equal goodness of fit. The w 0 w a CDM model is not a significant improvement over ΛCDM 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 2.6 σ suspiciousness tension. The constraint on S 8 = σ 8 √Ω m /0.3 is robust to opening up the parameter space for cosmic shear. Adding all external datasets to KiDS-Legacy, we find S 8 = 0.816 ± 0.006 in ΛCDM and S 8 = 0.837 ± 0.008 in w 0 w a CDM for all probes combined.