Characterization of strong preserver operators of convex equivalent on the space of all real sequences tend to zero


Noha Eftekhari, Ali Bayati Eshkaftaki




In this work we consider all bounded linear operators T : c 0 → c 0 that preserve convex equivalent relation ∼ c on c 0 and we denote by P ce (c 0) the set of such operators. If T strongly preserves convex equivalent, we denote them by P sce (c 0). Some interesting properties of P ce (c 0) are given. For T ∈ P ce (c 0), we show that all rows of T belong to 1 and for any j ∈ N, we have 0 ∈ Im(Te j), also there are a, b ∈ Im(Te j) such that co(Te j) = [a, b]. It is shown that all row sums of T belong to [a, b]. We characterize the elements of P ce (c 0), and some interesting results of all T ∈ P sce (c 0) are given, for example we prove that a = 0 < b or a < 0 = b. Also the elements of P sce (c 0) are characterized. We obtain the matrix representation of T ∈ P sce (c 0) does not contain any zero row. Some relevant examples are given