“…In the super critical case the scattering problem was studied in papers [3], [4], [8], [17], [19], [23], [24], [25] and in the critical case it was treated in [2], [11], [15], [20], [21]. The existence of modified scattering states was shown in papers [11], [15], [20] and modified wave operators were constructed in [2], [21]. In our previous paper [15] we considered the Cauchy problem (1.1) with cubic derivative nonlinearity (1.2), when the coefficient δ = 1.…”