Confused about Dirac notation

[theFuture]

So in my problem set I'm asked to solve for the "new energies of the system" I'm given the initial energies of this system and told a new potential is added. I know all the matrix elements. I solved for H|psi> so where do I go from here for the energies?

[sinyud]

I'm not sure, but can't you just solve H|psi> = E |psi> for the new Hamiltonian which is defined by

H=-hbar^2/2m Laplacian +Vold+Vnew

[theFuture]

That's what I was thinking but I was curious if there was some other trick buried in the Dirac stuff. Thanks.

[Kane O'Donnell]

The lecturer might be asking you to use pertubation theory - is the new potential small compared to the old?


Kane

[humanino]

I think Kane is right.

You can check wikipedia (http://en.wikipedia.org/wiki/Bra-ket_notation) about the Dirac notation.