In this study the interaction between self-excited and paramet rically excited oscillations in two-degree-of-freedom systems with quadratic nonlinearities is investigated. The fundamental parametric resonance of the first mode and 3:1 internal resonance is considered, followed by 1:2 internal and parametric resonances of the second mode. The method of multiple time scales is applied to derive f...

In this paper, by including Raman scattering in the coupled-mode equations, the scalar modulation instability in photonic crystal fibers is investigated. The evolution of the pump, Stokes and anti-Stokes waves along the fiber as well as the conversion efficiency for two cases, with and without Raman effect, are studied. The effect of anti-Stokes seed and the pump depletion on the evolution of S...

Parametric decay instability of lower hybrid waves plays an important role in plasma heating. Simulation such requires inclusion both electron and ion kinetics with a realistic mass ratio. In this work, the gyrokinetic fully kinetic (GeFi) particle simulation model is used to study parametric instabilities uniform, magnetized plasmas. A pump electric field near frequency imposed, which treated ...

We find evidence for the first observation of parametric decay instability (PDI) in lower solar atmosphere. Specifically, we that power spectrum density fluctuations near transition region resembles velocity fluctuations, but with frequency axis scaled up by about a factor two. These results are from an analysis Si IV lines observed Interface Region Imaging Spectrometer (IRIS) polar coronal hol...

Parametric resonance has been well established in many areas of science, including the stability of ships, the forced motion of a swing and Faraday surface wave patterns on water. We have previously investigated a linear parametrically driven torsional oscillator and along with other groups have mentioned applications including mass sensing, parametric amplification, and others. Here, we thorou...

We demonstrate that cosmological perturbations can undergo amplification by parametric resonance during the preheating period following inflation, even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial in order to determine the strength of the instability. To extract specific signatures of the oscillat...