Periodic L²-function decomposes into orthogonal trigonometric basis: f(x) = Σ c_n e^{inx}. Carleson 1966 a.e. convergence for L². Gibbs phenomenon at jump discontinuities. Foundation of harmonic analysis.
Periodic L²-function decomposes into orthogonal trigonometric basis: f(x) = Σ c_n e^{inx}. Carleson 1966 a.e. convergence for L². Gibbs phenomenon at jump discontinuities. Foundation of harmonic analysis.