A continuity equation compatible basis for Effective Field Theory of Dark Energy

TL;DR

This paper introduces a new basis for the Effective Field Theory of Dark Energy, based on a continuity equation constraint, to ensure clearer physical interpretation of the background operators.

Contribution

It proposes a physically motivated continuity equation compatible basis for EFT of Dark Energy, improving interpretability of the operators.

Findings

The CEC basis aligns with physical continuity equations.

It enhances the physical interpretability of EFT operators.

Provides a new framework for analyzing dark energy models.

Abstract

The Effective Field Theory (EFT) of Dark Energy (DE) is a model independent framework that allows for the description of a wide class of dark energy and modified gravity models. This is achieved by extending the Hilbert Einstein action through the introduction of time dependent functions. However, the choice of these functions and thus the operator basis is not unique. In this paper, we propose a physically motivated constraint based on the continuity equation, leading to a continuity equation compatible (CEC) basis that ensures a clear physical interpretation of the background EFT operators.