“…If the friction coefficient α > 0, then σ(A N,w ) ⊂ (0, ∞), hence the equilibrium u * = 0 of (3.4) is exponentially stable in X w γ,1 , by the principle of linearized stability (see e.g. [15,21]). Choosing u 0 X w γ,µc sufficiently small, then u(t, u 0 ) is arbitrarily close to u * = 0 in B (Ω) for µ ∈ (1/p, 1/2) and (3.7), that for eachε > 0 there existsr > 0 such that for all s ∈ [δ, a] we have u(s, u 0 ) Xγ,µ ≤ε provided u 0 X w γ,µ ≤r.…”