Instability of bound states of time-periodic systems.
(by Kenji Yajima)
The bound states of time periodic Schrödinger equations
are unstable under small perturbations which satisfy
the Fermi-Golden rule. We show that the potentials which
violate the Fermi-Golden rule are confined in a manifold
of infinite codimensions in a space of potentials, and
that the survival probability of bound states decays
exponentially for the time O(log μ), where μ
is the size of the perturbation.