"rapid fluctuation" is a correct phrase that can be used in written English.
It is usually used to describe a situation where something is changing rapidly or fluctuating rapidly. For example: "The stock prices experienced a rapid fluctuation during market hours."
One hallmark of the minimally conscious state is a rapid fluctuation between levels of awareness.
Secondly, the power budgets of many-core system might undergo a rapid fluctuation.
"This rapid fluctuation makes it very difficult to determine a long-term picture, though we hope when we have finished taking measurements in 2014 that we will have a better idea".
Among the results of subsequent balloon experiments launched from Texas and Australia was the discovery of the first rapid fluctuation of an X-ray source, a 10-minute flare from Sco X-1 (lew68).
The particles — bits of leaf, for example — suspended from its ceiling all vibrate in the air, keeping up a shimmering, minuscule, rapid fluctuation that's a counterpart to the heavier, slower progress of the performers.
In an FM (frequency-modulation) system, which is used by both television and FM radio stations, audio information is contained in the rapid fluctuation of the frequency in a narrow range around the frequency of the carrier wave.
Tells about the rapid fluctuations of weather.
Rapid fluctuations in prices tend to generate lots of buying and selling among clients.
Instead, rapid fluctuations in the force values were observed.
Photosynthetic organisms growing in nearly all environments must cope with rapid fluctuations in light intensity.
Others are new: changing family compositions because of HIV, increasing frequency of droughts and rapid fluctuations in international commodity prices.
