Coupled oscillators (Q1331338)

Modal coupling oscillation models for the stellar radial pulsation and coupled oscillators are reviewed. Coupled oscillations with the second- order and the third-order terms seem to behave non-systematically. Using the equation of Schwarzschild and Savedoff with the dissipation term of van der Pol's type which is third-order, we demonstrate the effect of each term. The effects can be understood in the terms of the nonlinear dynamics, that is, phase-locking, quasi-periodicity, period doubling and chaos.