I have a question about Fourier Series. In some books the author says : "It is difficult to talk about Fourier Series of non - Lebesgue integrable function" What does it mean really? What can we say about Fourier series of $f\notin L^1[-\pi,\pi]$??
2026-03-31 21:13:24.1774991604
What is the difficulty in talking about Fourier Series of non-Lebesgue integrable functions?
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