The phrase "underlying assumption behind" is correct and acceptable in written English.
You can use it when you want to refer to the hidden, unspoken basis for a particular idea or opinion. For example, "The underlying assumption behind his suggestion is that we have unlimited resources to devote to this project."
While making his long-anticipated speech to his players before the first full workout of the season, Collins related how embarrassed he was by the underlying assumption behind that question: that the Mets had not been playing hard.
The underlying assumption behind nearly all encryption ciphers used today is that their complexity precludes any attempt by hackers to break them, as it would take years for even our most advanced conventional computers to do so.
The underlying assumption behind the concept of the comparative safety assessment is that traditionally cultivated plants are considered safe due to a history of safe use for human and animal consumption [2, 4].
However, the underlying assumption behind the performance in[16] is that every transmitter knows the link scheduling status of all other links a priori, which cannot be implemented in practice.
This constitutes the underlying assumption behind the use of electrical point locators commonly used in clinical practice and research.
The underlying assumption behind the tracking method is that the movements of most of the cells are highly correlated according to shifts in the worm's body.
It is important to articulate the objectives and underlying assumptions behind a growing body of experimental research in conceptual modeling.
These predictions were based on the extrapolation of trends derived from previous vehicle technologies, expert opinions, and forecasts of supply-side variables with very little emphasis on the underlying assumptions behind these predictions.
Here I provide a critical overview of the suggested mechanisms for coupling synaptic stimulation to transcription, the underlying assumptions behind them and their plausible physiological significance.
The unspoken, unquestioned, and underlying assumption, especially of people 75 and older, was that marriage would last forever.
The underlying assumptions upon which Trident rests no longer ring true.
