Publications Meetings The Profession Membership Programs Math Samplings Policy & Advocacy In the News About the AMS
|
   
Available in electronic format
Available in print format
Proceedings of the American Mathematical Society
Proceedings of the American Mathematical Society
ISSN 1088-6826(e) ISSN 0002-9939(p)

     

Ferenc Lukács type theorems in terms of the Abel-Poisson mean of conjugate series

Author(s): Ferenc Móricz
Journal: Proc. Amer. Math. Soc. 131 (2003), 1243-1250.
MSC (2000): Primary 42A50, 42A16
Posted: September 5, 2002
MathSciNet review: 1948116
Retrieve article in: PDF
This article is available free of charge

Abstract | References | Similar articles | Additional information

Abstract: A theorem of Ferenc Lukács determines the generalized jumps of a periodic, Lebesgue integrable function $f$ in terms of the partial sum of the conjugate series to the Fourier series of $f$. The main aim of this paper is to prove an analogous theorem in terms of the Abel-Poisson mean. We also prove an estimate of the partial derivative (with respect to the angle) of the Abel-Poisson mean of an integrable function $F$ at those points at which $F$ is smooth. Finally, we reveal the intimate relation between these two results.


References:

1.
L. Fejér, Über die Bestimmung des Sprunges der Funktion aus ihrer Fourierreihe, J. reine angew. Math. 142 (1913), 165-188.

2.
F. Lukács, Über die Bestimmung des Sprunges einer Funktion aus ihrer Fourierreihe, J. reine angew. Math. 150 (1920), 107-112.

3.
A. Zygmund, Smooth functions, Duke J. 12 (1945), 47-76. MR 7:60b

4.
A. Zygmund, Trigonometric series, Vol. 1, Cambridge Univ. Press, Cambridge, UK, 1959. MR 21:6498

Similar Articles:

Retrieve articles in Proceedings of the American Mathematical Society with MSC (2000): 42A50, 42A16

Retrieve articles in all Journals with MSC (2000): 42A50, 42A16


Additional Information:

Ferenc Móricz
Affiliation: Bolyai Institute, University of Szeged, Aradi Vértanúk Tere 1, 6720 Szeged, Hungary
Email: moricz@math.u-szeged.hu

DOI: 10.1090/S0002-9939-02-06669-8
PII: S 0002-9939(02)06669-8
Keywords: Function of bounded variation, induced Borel measure, Fourier series, theorem of Fej\'er, conjugate series, generalized jump, theorem of Ferenc Luk\'acs, Abel-Poisson mean, smoothness, Zygmund classes $\lambda_*$ and $\Lambda_*$.
Received by editor(s): June 21, 2001
Received by editor(s) in revised form: December 3, 2001
Posted: September 5, 2002
Additional Notes: This research was started during the author's visit to the Université de Paris-Sud, Orsay, in May 2001, and it was partially supported by the Hungarian National Foundation for Scientific Research under Grant T 029 094
Communicated by: Andreas Seeger
Copyright of article: Copyright 2002, American Mathematical Society




AMS and Social Media LinkedIn Facebook Podcasts Twitter YouTube RSS Feeds Blogs Wikipedia