title: Unstable semiclassical trajectories in tunneling.
abstract: Some tunneling phenomena are described, in the semiclassical approximation, by unstable complex trajectories. We develop a systematic procedure to stabilize the trajectories and to calculate the tunneling probability, including both the suppression exponent and prefactor. We find that the instability of tunneling solutions modifies the power-law dependence of the prefactor on Planck's variant as compared to the case of stable solutions.
authors.affiliation: Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312, Russia.
authors.forename: D G
authors.initials: DG
authors.lastname: Levkov
authors.forename: A G
authors.initials: AG
authors.lastname: Panin
authors.forename: S M
authors.initials: SM
authors.lastname: Sibiryakov