 Fourier integral operator

The Fourier integral operator is a mathematical operator used in the context of Fourier analysis and signal processing. It is designed to generalize the concept of the Fourier transform and is particularly useful for analyzing functions in terms of their frequency components. The Fourier integral operator transforms a function defined in one domain (often time or space) into its representation in the frequency domain. ### Definition Let \( f(x) \) be a function defined on the real line.