We assume that the sequence ck, k ≥ 0, is regularly varying with index −β, β ∈ (1/2, 1) (written as ck ∈ RV−β). This means that ck ∼ k L0(k) as k → ∞, where L0 is slowly varying at infinity (see e.g. [2, Sections 1.4, 1.5] for the definition of slowly varying functions). We shall refer to all such models as long range dependent (LRD) linear processes. In particular, by the Karamata Theorem, the...