$f(T)$ cosmology in the regime of quasar observations

TL;DR

This paper explores $f(T)$ cosmology using quasar observations and local measurements to address the Hubble constant tension, suggesting quasars can help relax this discrepancy.

Contribution

It introduces calibrated quasar datasets as high-redshift standard candles and demonstrates their potential to reduce the $H_0$ tension in cosmology.

Findings

Quasar datasets can relax the $H_0$ tension at 2σ.

Combining quasars with local measurements supports higher $H_0$ values.

Quasars are promising probes for cosmological tensions.

Abstract

The open problems related to cosmological tensions in current times have opened new paths to study new probes to constrain cosmological parameters in standard and extended cosmologies, in particular, to determine at a local level the value of the Hubble constant $H_0$, through independent techniques. However, while standard Cosmological Constant Cold Dark Matter ($\Lambda$CDM) model has been well constrained and parts of extended cosmology have been intensively studied, the physics behind them aspects restrains our possibilities of selecting the best cosmological model that can show a significant difference from the first model. Therefore, to explore a possible deviation from a such model that can explain the current discrepancy on the $H_0$ value, in this work we consider adding the current local observables, e.g. Supernovae Type Ia (SNIa), $H(z)$ measurements, and Baryon Acoustic Observations (BAO) combined with two new calibrated Quasars (QSO) datasets using ultraviolet, x-ray and optical plane techniques. While these can be identified as part of the high-redshift standard candle objects, the main characteristics of these are based on fluxes distributions calibrated up to $z \sim 7 $. We consider five $H_0$ prior scenarios to develop these calibrations. Furthermore, we found that our estimations provide the possibility to relax the $H_0$ tension at 2$\sigma$ using a QSO ultraviolet sample in combination with late measurements showing higher values of $H_0$. Our results can be an initial start for more serious treatments in the quasars physics from ultraviolet, x-ray, and optical plane techniques behind the local observations as cosmological probes to relax the cosmological tensions problems.