On the (P) summability of a sequence of Fourier coefficients
Siyaram (1974)
Matematički Vesnik
George Tephnadze (2015)
Colloquium Mathematicae
We investigate convergence and divergence of specific subsequences of partial sums with respect to the Walsh system on martingale Hardy spaces. By using these results we obtain a relationship of the ratio of convergence of the partial sums of the Walsh series and the modulus of continuity of the martingale. These conditions are in a sense necessary and sufficient.
Tevzadze, V. (2005)
Acta Mathematica Academiae Paedagogicae Nyí regyháziensis. New Series [electronic only]
Drihem, Douadi, Moussai, Madani (2006)
International Journal of Mathematics and Mathematical Sciences
Włodzimierz Łenski, Bogdan Roszak (2008)
Banach Center Publications
We present an estimate of the (C,1)(E,1)-strong means with mixed powers of the Fourier series of a function as a generalization of the result obtained by M. Yildrim and F. Karakus. Some corollaries on the norm approximation are also given.
Nguyen Xuan Thao (2010)
Mathematical Problems in Engineering
Václav Stanček (1990)
Časopis pro pěstování matematiky
Aline Bonami, Tadeusz Iwaniec, Peter Jones, Michel Zinsmeister (2007)
Annales de l’institut Fourier
The point-wise product of a function of bounded mean oscillation with a function of the Hardy space is not locally integrable in general. However, in view of the duality between and , we are able to give a meaning to the product as a Schwartz distribution. Moreover, this distribution can be written as the sum of an integrable function and a distribution in some adapted Hardy-Orlicz space. When dealing with holomorphic functions in the unit disc, the converse is also valid: every holomorphic...
Alexander Nagel, Elias M. Stein (2004)
Revista Matemática Iberoamericana
We establish Lp-boundedness for a class of product singular integral operators on spaces M = M1 x M2 x . . . x Mn. Each factor space Mi is a smooth manifold on which the basic geometry is given by a control, or Carnot-Carathéodory, metric induced by a collection of vector fields of finite type. The standard singular integrals on Mi are non-isotropic smoothing operators of order zero. The boundedness of the product operators is then a consequence of a natural Littlewood- Paley theory on M. This in...
Lai-Yi Zhu, Da-Peng Zhou (2017)
Czechoslovak Mathematical Journal
Using undergraduate calculus, we give a direct elementary proof of a sharp Markov-type inequality for a constrained polynomial of degree at most , initially claimed by P. Erdős, which is different from the one in the paper of T. Erdélyi (2015). Whereafter, we give the situations on which the equality holds. On the basis of this inequality, we study the monotone polynomial which has only real zeros all but one outside of the interval and establish a new asymptotically sharp inequality.
Paolo Codecà (1984)
Rendiconti del Seminario Matematico della Università di Padova
Carolyn P. Johnston (1997)
The journal of Fourier analysis and applications [[Elektronische Ressource]]
A. Kamaly, A. M. Stokolos (2002)
Colloquium Mathematicae
The result of this article together with [1] and [4] gives a full quantitative description of a Fatou type property for functions from Hardy classes in the upper half plane.
Fujita, K. (2010)
Fractional Calculus and Applied Analysis
MSC 2010: 42C40, 94A12On the blind source separation problem, there is a method to use the quotient function of complex valued time-frequency informations of two ob-served signals. By studying the quotient function, we can estimate the number of sources under some assumptions. In our previous papers, we gave a mathematical formulation which is available for the sources with-out time delay. However, in general, we can not ignore the time delay. In this paper, we will reformulate our basic theorems...
Mikko Kemppainen (2011)
Studia Mathematica
This paper studies a new maximal operator introduced by Hytönen, McIntosh and Portal in 2008 for functions taking values in a Banach space. The -boundedness of this operator depends on the range space; certain requirements on type and cotype are present for instance. The original Euclidean definition of the maximal function is generalized to σ-finite measure spaces with filtrations and the -boundedness is shown not to depend on the underlying measure space or the filtration. Martingale techniques...
Lakhdar Tannech Rachdi, Ahlem Rouz (2009)
Annales mathématiques Blaise Pascal
We characterize the range of some spaces of functions by the Fourier transform associated with the Riemann-Liouville operator and we give a new description of the Schwartz spaces. Next, we prove a Paley-Wiener and a Paley-Wiener-Schwartz theorems.
Łenski, Włodzimierz (2001)
Applied Mathematics E-Notes [electronic only]
Szal, Bogdan (2008)
JIPAM. Journal of Inequalities in Pure & Applied Mathematics [electronic only]
Włodzimierz Łenski, Maria Topolewska (1998)
Mathematica Bohemica
Estimates of the strong means of Marcinkiewicz type with the Cesaro means of negative order in one of the variables instead of square partial sums are obtained by characteristics constructed on the basis of moduli of continuity.
Bogdan Szal (2011)
Banach Center Publications
We will generalize and improve the results of T. Singh [Publ. Math. Debrecen 40 (1992), 261-271] obtaining the L. Leindler type estimates from [Acta Math. Hungar. 104 (2004), 105-113].