LAUSR

In this paper, we consider the Moore–Gibson–Thompson equation with a memory term in the subcritical case, which arises in high-frequency ultrasound applications accounting for thermal flux and molecular relaxation times. For a class of relaxation functions satisfying for H to be increasing and convex function near the origin and to be a nonincreasing function, we establish the optimal explicit and general energy decay result, from which we can recover the earlier exponential rate in the special case.