Speaker
Description
Model-independent approaches have gained increasing attention as powerful tools to investigate persistent tensions between cosmological observations and $\Lambda$CDM predictions. Building on our previous work, MNRAS 523 (2023) 3, 3406-3422, we present a follow-up analysis of the model-independent calibration of both the local and inverse distance ladders using cosmic chronometers (CCH) data and the Gaussian Processes technique. We constrain the SNIa absolute magnitude, $M$, and the comoving sound horizon at the baryon-drag epoch, $r_d$, while simultaneously deriving a measurement of the spatial curvature parameter, $\Omega_k$, using CCH with DESY5 and DESI DR1/DR2. Our results show a compatibility with a flat universe at $\sim1.7\sigma$, weaker than that observed with Pantheon+ SNIa, while the ladders calibrators read $M=-19.324_{-0.095}^{+0.092}$ and $r_d = (144.00^{+5.38}_{-4.88}$) Mpc. As current uncertainties limit our ability to arbitrate the Hubble tension, we present for the first time a forecast analysis for the triad $(M, \Omega_k, r_d)$ to explore the constraining power of our methodology with future SNIa, CCH, and BAO observations from surveys such as LSST, Euclid, and DESI. We find that, in an optimistic scenario, upcoming data will improve agnostic constraints on the ladder calibrators - $M$ by $\sim$54%, $r_d$ by $\sim$66% - which enable us to constrain $H_0$ at a 2% level. Precision on $\Omega_k$ will increase by $\sim50%$. Our analysis outlines which improvements in future data - whether in quality, quantity, or redshift coverage - are likely to have the greatest impact on tightening these constraints.
| Other topic / keywords: | Tensions/Status of LCDM |
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