Talk:Plancherel theorem

What is the Plancherel transform
The article mentions the Plancherel transform which neither has a wikipedia entry nor is defined in the article. What I learned from the german version is that the "Plancherel transform" or "Fourier-Plancherel transform" is similar to the Fourier transform but defined for L2 instead of L1. Can anyone confirm this and add it to the article please? Thanks Upps, just saw the definition in the text --Nobelium (talk) 13:07, 31 August 2018 (UTC)