Lipót Fejér (1880-1959)

  • Alternative spelling: Fejer
  • Szegö, G., The contribution of L. Fejér to the constructive function theory, in Proceedings of the Conference on Constructive Theory of Functions, edited by G. Alexitis, S. B. Stechkin, pp. 19-26, Budapest, 1972.
  • Fejér, L., Sur les fonctions bornees et integrables, Comptes Rendus Hebdomadaries, Seances de l'Academie de Sciences, Paris, 131 (1900), 984-987 (in equation (2), 1/2 cos --> 1/2 + cos). This fundamental paper formed the basis of Fejér's doctoral thesis obtained in 1902 from the University of Budapest, under the supervision of H. A. Schwarz. Fejér was 20 years old when this paper appeared. The paper contains the "classic" theorem on Cesaro (C,1) summability of Fourier series, thus providing a direct constructive proof of Weierstrass' Theorem.
  • Fejér, L., Über Interpolation, Nachrichten der Gesellschaft der Wissenschaften zu Göttingen Mathematisch-physikalische Klasse, 1916, 66-91. This is where Fejer introduced what we now call the Hermite-Fejer Interpolation operator (based on the zeros of the Chebyshev polynomial), and proved the uniform convergence of the sequence of these polynomials to the function being interpolated.

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