An Awesome Hypothesis for Dark Energy : The Abnormally Weighting Energy

TL;DR

This paper proposes the Abnormally Weighting Energy hypothesis, suggesting dark energy results from a violation of the weak equivalence principle at cosmic scales, leading to cosmic acceleration without requiring a violation of the strong energy condition.

Contribution

It introduces a novel dark energy mechanism based on WEP violation in the dark sector, with natural convergence to general relativity and compatibility with supernovae data.

Findings

Accounts for supernovae data with various dark sector couplings

Predicts a transition to Einstein-de Sitter expansion regime

Provides a natural convergence mechanism to GR

Abstract

We introduce the Abnormally Weighting Energy (AWE) hypothesis in which dark energy (DE) is presented as a consequence of the violation of the weak equivalence principle (WEP) at cosmological scales by some dark sector. Indeed, this implies a violation of the strong equivalence principle (SEP) for ordinary matter and consequent cosmic acceleration in the observable frame as well as variation of the gravitational constant. The consequent DE mechanism build upon the AWE hypothesis (i) does not require a violation of the strong energy condition $p<-\rho c^2/3$, (ii) assumes rather non-negligible direct couplings to the gravitational scalar field (iii) offers a natural convergence mechanism toward general relativity (iv) accounts fairly for supernovae data from various couplings and equations of state of the dark sector as well as density parameters very close to the ones of the concordance model $\Lambda CDM$. Finally (v), this AWE mechanism typically ends up with an Einstein-de Sitter expansion regime once the attractor is reached.