Coupled Multi-Proca Vector Dark Energy

Understand

We study a new class of vector dark energy models where multi-Proca fields $A_\mu^a$ are coupled to cold dark matter by the term $f(X)\tilde{\mathcal{L}}_{m}$ where $f(X)$ is a general function of $X\equiv -\frac{1}{2}A^\mu_ a A^a_\mu$ and $\tilde{\mathcal{L}}_{m}$ is the cold dark matter Lagrangian.

• From here, we derive the general covariant form of the novel interaction term sourcing the field equations.
• This result is quite general in the sense that encompasses Abelian and non-Abelian vector fields.
• In particular, we investigate the effects of this type of coupling in a simple dark energy model based on three copies of canonical Maxwell fields to realize isotropic expansion.