Gravity is controlled by cosmological constant

TL;DR

This paper presents a D-braneworld model where the cosmological constant naturally arises from the effective gravitational coupling, linking the observed small value of the cosmological constant to brane tension and charge configurations.

Contribution

The study derives an effective gravitational equation in a two D-braneworld setup showing the cosmological constant is proportional to the gravitational constant, providing a natural explanation for its observed value.

Findings

Effective gravitational constant is proportional to the cosmological constant.

Proper brane tension and charge tuning can match observed cosmological constant.

The model links the cosmological constant to brane-world parameters.

Abstract

We discuss a Randall-Sundrum-type two D-braneworld model in which D-branes possess different values of the tensions from those of the charges, and derive an effective gravitational equation on the branes. As a consequence, the Einstein-Maxwell theory is realized together with the non-zero cosmological constant. Here an interesting point is that the effective gravitational constant is proportional to the cosmological constant. If the distance between two D-branes is appropriately tuned, the cosmological constant can have a consistent value with the current observations. From this result we see that, in our model, the presence of the cosmological constant is naturally explained by the presence of the effective gravitational coupling of the Maxwell field on the D-brane.