“…Over the last years, the Moore -Gibson -Thompson (MGT) equation (cf. [30,45]), a linearization of a model for the wave propagation in viscous thermally relaxing fluids, has been studied by several authors (see, for example, [13,20,19,28,18,27,7,11,26,12,25,37,3,10,38,5,6,4,8]).…”