Assumption V2 on page 1078 should read:
V2 There exist constants p ≥ 2, α0, α1, c , e ≥ 0 such that for any v∈R and a.e. t∈ [0,π] we have
V2 There exist constants p ≥ 2, α0, α1>0 such that for any v∈R and a.e. t∈ [0,π] we have
The author regrets that these corrections were not inserted at the stage of proofreading.