For the eigenvectors, assume that for some , and write . Then the equation reads , which, carrying out the operation, brings us to . Now solve for . What do you get?
Hi, here is my problem :
Let H be a Hilbert space with basis {u_k}_k>0.
Verify that the operator T defined by :
T(u_k) = 1/k . u_k+1
is compact but has no eigenvectors.
To show it is compact, I tried to use the definition : T is compact if any bounded sequence {f_k} in H has a subsequence {f_nk}_k>0 such that {T(f_nk)} converges.
I took a bounded sequence {f_k} in H and approximated the f_k's by linear combinations of the basis elements {u_k}. But I don't see where this is supposed to lead me.
For the eigenvectors, I am lost.
Any ideas ?
Thanks.