Dark D-Brane Cosmology: from background evolution to cosmological perturbations

Understand

We study the cosmological predictions of the dark D-brane model, in which dark matter resides on a D-brane moving in a higher-dimensional space.

• By construction, dark matter interacts only gravitationally with the standard model sector in this framework.
• The dark energy scalar field is associated with the position of the D-brane, and its dynamics is encoded in a Dirac-Born-Infeld action.
• On the other hand, dark matter is identified with matter on the D-brane, that naturally couples to dark energy \textit{via} a disformal coupling.