“…Let Ψ be a nonconstant complex holomorphic function defined on a connected open set containing σ p (L ). Then by the usual Riesz functional calculus (see [14,Definition 10.26 at page 261]), it follows that the semigroup T (t ) = e t Ψ(L ) , where t ≥ 0, (1) consists of bounded linear operators on L p (X) for every p ∈ [1, ∞]. Moreover, the semigroup T (t ) is strongly continuous, that is, T (t ) f − f L p (X) → 0 as t → 0, for every f ∈ L p (X).…”