  Conductance through weak constrictions in Luttinger liquids is shown to
vanish with frequency $\omega$ as $c_1 \omega^2 + c_2 \omega^{2/g - 2}$, where
$g$ is a dimensionless parameter characterizing the Luttinger liquid phase, and
$c_1$ and $c_2$ are nonuniversal constants. The first term arises from the ^^
Coulomb blockade' effect and dominates for $g < 1/2$, whereas the second
results from eliminating high-energy modes and dominates for $g > 1/2$.
