| Abstract: | We find statistical evidence for a mismatch between the (global) spatial curvature parameter K in the geodesic equation for incoming photons, and the corresponding parameter in the Friedmann
equation that determines the time evolution of the background spacetime and its perturbations. The mismatch, merely a ‘curvature-slip’, is especially evident when local prior on the current expansion rate is assumed. This result is based on joint analyses of cosmic mi-
crowave background (CMB) observations with the PLANCK (PL) satellite, first year results of the Dark Energy Survey (DES), Baryonic Oscillation (BAO) data, and - at a lower level of significance - also on Pantheon SNIa (SN) catalog. For example, the betting odds against the Null
Hypothesis (i.e. vanishing curvature slip) are greater than 10^{7} :1, 1400:1 and 1000:1 when PL, PL+DES, and
PL+BAO, respectively, are considered (subject to local expansion rate prior). Datasets involving SNIa weaken this curvature slip considerably. Notably, even when the local expansion rate prior is not imposed the betting odds for the rejection of the Null Hypothesis are 70:1 and 160:1 in cases where PL+DES and PL+BAO are considered. When local expansion rate prior is imposed, global fit of the modified model (that allows for a nonvanishing ‘curvature slip’) strongly outperforms that of ΛCDM. Our finding could possibly be interpreted as an inherent inconsistency between the (idealized) maximally symmetric nature of the FRW metric, and the dynamical evolution of the GR-based homogeneous and isotropic ΛCDM model. As such it implies that there is an apparent tension between the metric curvature and the curvature-like term
in the time evolution of redshift. |