“…Explicitly, the author showed that if the above problem (1.4) has a nontrivial solution, then 5) which yields the standard Lyapunov inequality (1.2) if we take α = 2 in (1.5), where Γ is the gamma function. From then on, some Lyapunov-type inequalities for other fractional boundary value problems were established, see, for example, [7,10,11,14,16] and the references listed therein. On the other hand, there are some papers on Lyapunov-type inequalities for partial differential equations, we refer the reader to [2,3,9] for related results.…”