> The non-linear Fourier transform (..) seems impressively obscure (I know of a total of one book reference) Are those talking about the same thing? [Informat

> The non-linear Fourier transform (..) seems impressively obscure (I know of a total of one book reference) Are those talking about the same thing? [Information Transmission using the Nonlinear Fourier Transform, Part I: Mathematical Tools](https://arxiv.org/abs/1202.3653 https://arxiv.org/abs/1202.3653) [Nonlinear Fourier Analysis](https://arxiv.org/abs/1201.5129 https://arxiv.org/abs/1201.5129)