Plancherel theorem
The set of Plancherel 's a statement from the mathematical branch of Fourier analysis, which belongs to the functional analysis. The theorem states that the Fourier transform on the space of square integrable functions is an isometry, so that a function and its Fourier transform have the same standard. In 1910, the statement by Michel Plancherel was proved after the theorem is named.
Statement
There exists an isometry which is unitary and clearly by
Is intended for all, the Fourier transform and the Schwartz space designated.