  The orbital eccentricity of a single planet around a component of a stellar
binary system with a sufficiently large mutual inclination angle is known to
oscillate on a secular timescale through the Kozai mechanism. We have
investigated the effects of the Kozai mechanism on double-planet systems in
binaries. The evolutionary sequence of a pair of planets under the influence of
a binary companion is fairly complex. Various dynamical outcomes are seen in
numerical simulations. One interesting outcome is the rigid rotation of the
planetary orbits in which the planetary orbital planes secularly precess in
concert, while the orbital eccentricities oscillate synchronously. In such
cases the outer planet acts as a propagator of the perturbation from the binary
companion to the inner planet and drives the inner planetary orbit to precess
at a rate faster than what is predicted by the Kozai mechanism.
