I'm currently writing a review paper on the accelerated expansion of the universe (focussing on scalar field models like quintessence) and was wondering if there is a specific name for the approximation used in obtaining the condition for cosmic acceleration, given by
$\dot{\phi}^2 < V(\phi)$.
When this is substituted into
$w = \frac{P}{\rho} = \frac{\frac{1}{2}\dot{\phi}^2 - V(\phi)}{\frac{1}{2}\dot{\phi}^2 + V(\phi)}$,
we get
$w < -\frac{1}{3}$,
which is the condition for cosmic acceleration. It is very similar to the slow-roll approximation used for inflation
$\dot{\phi}^2 \ll V(\phi)$.
Is there a name for this approximation?