ON A-STATISTICAL CLUSTER POINTS

Abstract. In this paper we study the concepts of statistical cluster points and statistical core of a sequence for C methods dened by deleting a set of rows from the Cesaro matrix C1: Also we get necessary conditions on the matrices A and B so that A and B are equivalent in the statistical convergence sense and, study the equality A(x) = B(x);where A(x) is the set of A-statistical cluster points of the real number sequence x. 1. introduction and notations In [5] Fridy introduced the concepts of statistical limit points and statis-tical cluster points of a number sequence. These concepts are compared to the usual concept of limit point of a sequence. In [6] Fridy and Orhan intro-duced the concepts of statistical limit superior and inferior. They have also given the denition of the statistical core of a real number sequence which is based on the idea of the statistical cluster points of the sequence, and proved the statistical core theorem. Those results have also been extended [7] to the complex case by them, too. In [2] Connor and Kline extended the concept of a statistical limit (cluster) point of a number sequence to a A-statistical limit (cluster) point where A is a nonnegative regular summability matrix. In [3] the present author extended the concepts of statistical limit superior and inferior (as introduced by Fridy and Orhan) to A-statistical limit superior and inferior and given some A-statistical analogue of properties of statistical limit superior and inferior for a sequence of real numbers. Also in [3] the concept of statistical core is extended to A-statistical core. In this paper we study the concepts of statistical cluster points and statis-tical core of a sequence for C methods, dened by deleting a set of rows fro