Metric f(R) gravity with dynamical dark energy as a scenario for the Hubble tension

Abstract We introduce a theoretical framework to interpret the Hubble tension, based on the combination of a metric f(R) gravity with a dynamical dark energy contribution. The modified gravity provides the non-minimally coupled scalar field responsible for the proper scaling of the Hubble constant, in order to accommodate for the local SNIa pantheon+ data and Planck measurements. The dynamical dark energy source, which exhibits a phantom divide line separating the low red-shift quintessence regime (−1 < w < −1/3) from the phantom contribution (w < −1) in the early Universe, guarantees the absence of tachyonic instabilities at low red-shift. The resulting H0(z) profile rapidly approaches the Planck value, with a plateau behaviour for z ≳ 5. In this scenario, the Hubble tension emerges as a low red-shift effect, which can be in principle tested by comparing SNIa predictions with far sources, like QUASARS and Gamma Ray Bursts.