In this paper, we discuss the Sturm-Liouville problems on the shrinking intervals. In the first part of this paper, we give a survey of a certain Sturm-Liouville equation on shrinking intervals and its physical background. Some pervious results are introduced briefly. And then we give some basic concept of regular(singular) Sturm-Liouville equation, eigenvalue , eigenfunction and so on.In the second and third part, with the idea of the paper [20], we establish results concerning the detailed asymptotic behavior of the eigenvalues of a class of regular Sturm-Liouville problems with general separated self-adjoim boundary conditions as the length of the interval shrinks to zero. The results are as follows:With aâ†'0+, consider equation(1)satisfy BC: Y(0) = 0,Y(a) = 0, we have: if R(0) > 0, thenλ0(a):-((q0)/(γ0))+ O(1/a),λγ(a)-((γπ)2p0)/(γ0))a-2;if R(0) = 0,Q(0)≠0, thenλ0(a)=O(a-(S+1)),λγ(a)-((p0μγ0)/(γS))a-(2+S); if R(0) = 0,Q(0) = 0, thenλγ(a)-((p0μγ0)/(γS))a-(2+S), if N≠S, thenλ0(a)= O(a-(S+1)), if N = S, thenλ0(a)=-((qN)/(γS))+O(a-(S+1)).(2)satisfy BC: Y(0) = 0, Y(a)H-p(a)Y'(a) = 0, we have: if R(0) > 0, thenλ0(a)= -((q0)/(γ0))-((H2)/p0γ0))+O(1/a),λγ(a)-((tγ2P0)/(γ0))a-2; if R(0) = 0,Q(0)≠0, thenλ0(a)=O(a-(S+1)),λγ(a)-((p0μγ0)/(γS))a-(2+S); if R(0) = 0,Q(0) = 0, thenλγ(a)-((p0μγ0)/(γS))a-(2+S), if N≠S, thenλ0(a)= O(a-(S+1)), if N = 5, thenλ0(a)=-((qN)/(γS))+O(a-(S+1)).(3)satisfy BC: Y(0)h-P(0)Y'(0) = 0,Y(a) = 0, we have: if R(0) > 0, thenλ0(a)= -((q0)/(γ0))+O(1/(a2)),λγ(a)-((tγ2p0)/(γ0))a-2; if R(0) = 0,Q(0)≠0, thenλ0(a)=O(a-(S+2))?λγ(a)- ((p0μγ0)/(γS))a-(2+S); if R(0) = 0,Q(0) = 0, thenλγ(a)-((p0μγ0)/(γS))a-(2+S),if N≠S,thenλ0(a)= O(a-(S+2)), if N = S, thenλ0(a)=-((qN)/(γS))+O(a-(S+2)).(4)satisfy BC: Y(0)h-P(0)Y'(0) = 0,Y(a)H-P(a)Y'(a) = 0, we have: if R(0) > 0, thenλ0(a)=-((q0)/(γ0))+(H-h)O(1/a2),λγ(a)-((tγ2p0)/(γ0))a-2; if R(0) = 0,Q(0)≠0, thenλ0(a)= O(a-(S+1)),λγ(a)-((p0μγ0)/(γS))a-(2+S); if R(0) = 0, Q(0) = 0, thenλγ(a)-((p0μγ0)/(γS))a-(2+S),if N≠S, thenλ0(a)=O(a-(S+1)), if N = S, thenλ0(a)=-((qN)/(γS))+O(a-(S+1)?... |