$H_0$ from cosmic chronometers and Type Ia supernovae, with Gaussian processes and the weighted polynomial regression method

TL;DR

This paper uses cosmic chronometers and Type Ia supernova data, applying Gaussian Processes and weighted polynomial regression to estimate the Hubble constant, finding results compatible with Planck but in tension with local HST measurements.

Contribution

It introduces a combined analysis of cosmic chronometers and supernova data using GPs and WPR to estimate H_0, providing a novel comparison with existing measurements.

Findings

H_0 from GPs: 67.99 ± 1.94 km/s/Mpc

H_0 from WPR: 68.90 ± 1.96 km/s/Mpc

Results are compatible with Planck and in ~2σ tension with HST

Abstract

We derive new constraints on the Hubble parameter $H_0$ using the available data on $H(z)$ from cosmic chronometers (CCH), and the Hubble rate data points from the supernovae of Type Ia (SnIa) of the Pantheon compilation and the Hubble Space Telescope (HST) CANDELS and CLASH Multy-Cycle Treasury (MCT) programs. We employ two alternative techniques, Gaussian Processes (GPs) and the Weighted Polynomial Regression (WPR) method, to reconstruct the Hubble function, determine the derived values of $H_0$, and compare them with the local HST measurement provided by Riess {\it et al.} (2018), $H_0^{{\rm HST}}=(73.48\pm1.66)$ km/s/Mpc, and with the Planck+$\Lambda$CDM value, $H_0^{{\rm P18}}=(66.88\pm 0.92)$ km/s/Mpc. With GPs we obtain $H_0=(67.99\pm 1.94)$ km/s/Mpc, and with the WPR method $H_0=(68.90\pm 1.96)$ km/s/Mpc. Both are fully compatible at $<1\sigma$ c.l., and also with $H_0^{{\rm P18}}$. In contrast, they are in $\sim 2\sigma$ tension with $H_0^{{\rm HST}}$.