In this thesis,We focus our attention on equations with magnetic field.First,we study the existence and concentrate behavior of solutions for following non-linear fractional Schrodinger equation with magnetic field (?) where ε>0 is a small parameter,0<s<1,2<p<2*=6/3-2s,(-△)As is the fractional magnetic Laplacian,V,K are both positive potentials.A(x)is a magnetic potential.When V,K,A satisfy suitable assumpt.ions,we prove the existence of a nontrivial solution by using variational methods for each ε>0 sufficiently small,and we complete the proof of concentrate behavior of solutions.Next,we use variational methods,combine with saddle point theory to study the following problem:(?)where Ω(?)R3 is a bounded open set with smooth boundary,A =(A1,A2,……An):is a magnetic field,such that A E Lloc2(RN),▽A:=-i▽ + A,-△A:=(-i▽+A)2.V(x)≥0 and it is continuous.And we implied that there are three solutions in this problem when f,V,h satisfy suitable assumptions. |