Screening away the $H_0$ tension

TL;DR

This paper proposes a dark non-linear electromagnetic sector that screens dark forces on small scales, which could increase local Hubble constant measurements and address the Hubble tension.

Contribution

It introduces a novel dark electromagnetic interaction with a screening mechanism that impacts cosmological dynamics and local velocity fields, offering a potential solution to the Hubble tension.

Findings

Dark electromagnetic forces can enhance local Hubble constant values.

Screening mechanism suppresses dark forces on small scales.

Potential explanation for dark flow phenomena.

Abstract

This Essay explores consequences of a dark non-linear electromagnetic sector in a Universe with a net dark charge for matter. The cosmological dynamics can be described by a Lema\^itre model and understood thanks to a screening mechanism driven by the electromagnetic non-linearities that suppress the dark force on small scales. Only at low redshift, when the screening scale enters the Hubble horizon, do cosmological structures commence to feel the dark repulsion. This repulsive force enhances the local value of the Hubble constant, thus providing a promising scenario for solving the Hubble tension. Remarkably, the dark electromagnetic interaction can have a crucial impact on peculiar velocities, i.e. introducing a bias in their reconstruction methods, and having the potential to explain the presence of a dark flow.