“…Decay estimates for waves on black hole spacetimes are obtained, for instance, in [1,3,14,15,16,25,26,28,40,41,30,31,52,54,55,43] and for Strichartz-type estimates in this context we refer to [42,57]. General one-dimensional wave equations with polynomially decaying potentials are studied in [24,10] and the semiclassical regime is considered in [11,9]. We also mention the recent [2] which deals with a complex potential.…”