Bilinearization of a Generalized Derivative Nonlinear Schrödinger Equation

A generalized derivative nonlinear Schrödingerequation, iq_t+q_xx+2iγ \mid q\mid ²q_x+2i(γ -1)q²q_x^\ast+(γ -1)(γ -2)\mid q\mid ⁴q=0, isstudied by means of Hirota's bilinear formalism. Soliton solutions areconstructed as quotients of Wronski-type determinants. A relationshipbetween the bilinear structure and gauge transformation is alsodiscussed.