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arXiv · 2605.25108

Pointwise behavior of SU(1,1) nonlinear Fourier transform

Sergey A. Denisov
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Abstract

We show that SU(1,1) NLFT can diverge pointwise for square-summable coefficients. As a consequence, we prove that the classical pointwise asymptotics of polynomials orthogonal on the unit circle can fail for measures in the Szeg\"o class. We also discuss some special cases when the pointwise convergence holds.

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BibTeXRIS

Sergey A. Denisov. 2026-05-24. Pointwise behavior of SU(1,1) nonlinear Fourier transform. https://arxiv.org/abs/2605.25108

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