We study parametric amplification of Kaluza-Klein (KK) modes in a higher (Formula presented) generalized Kaluza-Klein theory, which was originally considered by Mukohyama in the narrow resonance case. It was suggested that KK modes can be enhanced by an oscillation of a scale of compactification by the (Formula presented) sphere (Formula presented) and by the direct product (Formula presented) We extend this past work to the more general case where initial values of the scale of compactification and the quantum number of the angular momentum (Formula presented) of KK modes are not small. We perform analytic approaches based on the Mathieu equation as well as numerical calculations, and find that the expansion of the universe rapidly makes the KK field deviate from instability bands. As a result, KK modes are not enhanced sufficiently in an expanding universe in these two classes of models.
|ジャーナル||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|出版ステータス||Published - 2000|
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