1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quick question about bra-ket notation

  1. Jan 21, 2014 #1
    1. The problem statement, all variables and given/known data

    On Wikipedia there is an article about perturbation theory. To understand something I need to understand the following relation. They say:

    2. Relevant equations

    [itex]H |n> = E_n |n>[/itex]


    [itex]<n| H = <n| E_n[/itex]

    H is Hermitian.

    So: Why is this?

    3. The attempt at a solution

    I don't know if this is valid.

    [itex](H \cdot |n>)^\dagger = (E_n \cdot |n>)^\dagger[/itex]


    [itex]<n| H^\dagger = <n| E_n^\dagger[/itex]

    And since H is Hermitian and E_n is real, I get:

    [itex]<n| H = <n| E_n[/itex]

    Is this how things work?
  2. jcsd
  3. Jan 21, 2014 #2


    User Avatar

    Staff: Mentor

    That looks correct.
  4. Jan 21, 2014 #3
    Looks fine to me too.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Quick question about bra-ket notation
  1. Quick bra-ket question (Replies: 6)