subspace-diskcyclic sequences of linear operators

A sequence {tn}^∞n=1 of bounded linear operators on a separable infinite dimensional hilbert space h is called subspace-diskcyclic with respect to the closed subspace m⊆h, if there exists a vector x∈h such that the disk-scaled orbit {αtnx:n∈n,α∈c,|α|≤1}∩m is dense in m. the goal of this paper is the studying of subspace diskcyclic sequence of operators like as the well known results in a single operator case. in the first section of this paper, we study some conditions that imply the diskcyclicity of {tn}^∞n=1. in the second section, we survey some conditions and subspace-diskcyclicity criterion (analogue the results obtained by some authors in{6, 10, 11}) which are sufficient for the sequence {tn}^∞n=1 to be subspace-diskcyclic(subspace-hypercyclic).