How to Test Stringy Dark Energy?

It is suggested, by using a covariant lagrangian formalism to estimate the equation of state $w=p\mathrm{/}\rho$, that stringy dark energy predicts $w<-1$, a negative pressure larger in magnitude than that for a cosmological constant or quintessence. This would lead to a later transition from decelerating to accelerating cosmological expansion; $w=-4\mathrm{/}3$ is briefly considered as one illustrative example.