Riesz summation method
A method for summing series of numbers and functions; denoted by . A series is summable by the Riesz summation method to the sum if
where , , and is a continuous parameter. The method was introduced by M. Riesz  for the summation of Dirichlet series. The method is regular; when it is equivalent to the Cesàro summation method (cf. Cesàro summation methods), and these methods are compatible (cf. Compatibility of summation methods).
Riesz considered also a method in which summability of the series is defined by means of the limit of the sequence , where
This method is denoted by . The method is a modification of the method (when ) and is a generalization of it to the case of an arbitrary .
|||M. Riesz, "Une méthode de sommation équivalente à la méthode des moyennes arithmétique" C.R. Acad. Sci. Paris , 152 (1911) pp. 1651–1654|
|||F. Riesz, "Sur la sommation des séries de Dirichlet" C.R. Acad. Sci. Paris , 149 (1909) pp. 18–21|
|||G.H. Hardy, M. Riesz, "The general theory of Dirichlet series" , Cambridge Univ. Press (1915)|
|||G.H. Hardy, "Divergent series" , Clarendon Press (1949)|
|[a1]||K. Zeller, W. Beekmann, "Theorie der Limitierungsverfahren" , Springer (1970)|
Riesz summation method. I.I. Volkov (originator), Encyclopedia of Mathematics. URL: http://www.encyclopediaofmath.org/index.php?title=Riesz_summation_method&oldid=19011