Late-time approaches to the Hubble tension deforming H(z), worsen the growth tension

Abstract

Many late time approaches for the solution of the Hubble tension use late time smooth deformations of the Hubble expansion rate H(z) of the Planck18/ΛCDM best fit to match the locally measured value of H0 while effectively keeping the comoving distance to the last scattering surface and Ω0mh2 fixed to maintain consistency with Planck CMB measurements. A well known problem of these approaches is that they worsen the fit to low z distance probes. Here we show that another problem of these approaches is that they worsen the level of the Ω0m − σ8 growth tension. We use the generic class of CPL parametrizations corresponding to evolving dark energy equation of state parameter $w(z)=w_0+w_1\frac{z}{1+z}$ with local measurements H0 prior and identify the pairs (w0, w1) that satisfy this condition. This is a generic class of smooth deformations of H(z) that are designed to address the Hubble tension. We show that for these models the growth tension between dynamical probe data and CMB constraints is worse than the corresponding tension of the standard Planck18/ΛCDM model. We justify this feature using a full numerical solution of the growth equation and fit to the data, as well as by using an approximate analytic approach. The problem does not affect recent proposed solutions of the Hubble crisis involving a SnIa intrinsic luminosity transition at zt ≃ 0.01.

No-go guide for late-time solutions to the Hubble tension: Matter perturbations

“…This suggests that if late-time solutions are invoked to address the new physics required for resolving the Hubble tension, then the modifications must go beyond the background level [43,44]. Our conclusion is consistent with recent studies [114][115][116], together with the recent analytic criterion [117,118], rendering a no-go guide for the late-time solutions on the Hubble tension.…”

On the Robustness of the Constancy of the Supernova Absolute Magnitude: Non-parametric Reconstruction \& Bayesian approaches

“…Indeed, Refs. [55][56][57][58][59][60] suggest that a transition in the dark energy equation of state or in the absolute magnitude as a possible solution to the Hubble tension. In addition to the SNIa observations, we also make use of BAO measurements [39-52, 61, 62] in order to take a fuller account of the possible evolution of M B (z).…”

The Hubble Tension, the M Crisis of Late Time H(z) Deformation Models and the Reconstruction of Quintessence Lagrangians

“…• It worsens the growth tension of the ΛCDM model as it indicates larger values of the parameters σ 8 and Ω 0m than indicated by dynamical cosmological probes [6,7] • It provides a worse fit than ΛCDM to low z geometric probes such as SnIa and BAO [6].…”

“…However, since the measurements are made at different redshift ranges, the discrepancy can be reconciled by assuming a transition of the absolute magnitude M at z 0.01 by ∆M 0.02, as shown in Figure 1. This transition corresponds to brighter SnIa at high z (early times) compared to low z (late times) since the SnIa absolute Luminosity L is connected with the absolute magnitude as L ∼ 10 −2M/5 (7) H(z) deformations obtained by dynamical dark energy have been used as possible approaches to the Hubble tension. In this class of models, H(z) becomes deformed from its ΛCDM form (6) in such a way that the CMB anisotropy spectrum remains practically invariant while the Hubble parameter H 0 is shifted to the H R20 0 value (e.g., [6]).…”

“…It is stated that, being a w > −1 model (excluding the cosmological constant), it can only make the Hubble tension worse. In general, late time models trying to resolve the cosmological tensions do not succeed, as can also be seen in [7], where it is shown that late time approaches worsen the growth tension and in [6] where they worsen the fit, in comparison with the ΛCDM, when SNIa or BAO data are used. However, since the Hubble tension also manifests itself as an M-tension [84,85], a transition of M can be used for these models to fully resolve the Hubble tension, as shown in Figure 1 and discussed in detail in [20,86].…”