In mathematical analysis, the Rademacher–Menchov theorem, introduced by Rademacher ( 1922) and Menchoff ( 1923), gives a sufficient condition for a series of orthogonal functions on an interval to converge almost everywhere.

If the coefficients c_ν of a series of bounded orthogonal functions on an interval satisfy

${\displaystyle \sum |c_{\nu }|^{2}\log(\nu )^{2}<\infty }$

then the series converges almost everywhere.

• Menchoff, D. (1923), "Sur les séries de fonctions orthogonales. (Première Partie. La convergence.).", Fundamenta Mathematicae (in French), 4: 82–105, doi: 10.4064/fm-4-1-82-105, ISSN  0016-2736
• Rademacher, Hans (1922), "Einige Sätze über Reihen von allgemeinen Orthogonalfunktionen", Mathematische Annalen, 87, Springer Berlin / Heidelberg: 112–138, doi: 10.1007/BF01458040, ISSN  0025-5831, S2CID  120708120
• Zygmund, A. (2002) [1935], Trigonometric Series. Vol. I, II, Cambridge Mathematical Library (3rd ed.), Cambridge University Press, ISBN  978-0-521-89053-3, MR  1963498