Prove that Hermitian/Skew Herm/Unitary Matrix is a Normal Matrix

  • Thread starter Thread starter Wildcat04
  • Start date Start date
  • Tags Tags
    Matrix Normal
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 11K views
Wildcat04
Messages
33
Reaction score
0

Homework Statement


Show the proof that the following are all Normal Matrices
a. Hermitian
b. Skew Hermitian
c. Unitary

Homework Equations



Normal Matrices: A*A=AA*
Hermitian Matrices: A=A* or aij=a*ji
Skew Hermitian Matrices A=-A* or aij=-a*ji

The Attempt at a Solution



So far I have tried using the above information for Hermitian Matrices to try and prove that A*A=AA* but I keep getting answers I know not to be correct. I would appreciate a nudge in the correct direction so I can quit pulling my hair out. I have a feeling when I find the correct proof it will be quite obvious, but right now I am just missing something.
 
Physics news on Phys.org
If A is hermitian then A*=A. A*A=AA=AA*. How are you trying to do it?
 
I was trying to do it much more in depth using amn. It never occurred to me to use the basic matrix itself. Like I said, it was right in front of me. Thank you for the help!