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Updated: Jul 29, 2026

Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators
Published on: April 4, 2016
Comment on "Soliton ratchets induced by excitation of internal modes"
Niurka R Quintero1, Bernardo Sánchez-Rey, Jesús Casado-Pascual
1Departamento de Física Aplicada I, E. U. P., Universidad de Sevilla, Virgen de Africa 7, 41011 Sevilla, Spain. niurka@euler.us.es
Abstract:
Very recently Willis [Phys. Rev. E 69, 056612 (2004)] have used a collective variable theory to explain the appearance of a nonzero energy current in an ac-driven, damped sine-Gordon equation. In this Comment, we prove rigorously that the time-averaged energy current in an ac-driven nonlinear Klein-Gordon system is strictly zero.
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