Multiplicity of normalized solutions to biharmonic Schrödinger equation with mixed nonlinearities

This paper is concerned with the existence of multiple normalized solutions to the elliptic problems {Δ2u=λu+h(ϵx)|u|q−2u+|u|p−2uin RN,∫RNu2dx=c, where c, ϵ>0, N≥5, 20 and present a class of reasonable assumptions on h to guarantee that the numbers of normalized solutions are at least the numbers of global maximus points of h when ε is small enough and 0<c≤c0.