# Dirac's Coupling to an electromagnetic field and schroedingers

1. Apr 19, 2009

### g.bashyam

hi
i just read this article,which discussed about getting the Schroedinger's equation for a particle in a em field by transforming the psi, http://www.vttoth.com/gauge.htm .can anyone plz tell me if we can get the dirac's equation for a particle in a em field by transforming the psi
regards
bashyam govindhan

2. Apr 22, 2009

### dextercioby

As far as I know, the same calculations can be made for the Dirac Hamiltonian.

3. Apr 22, 2009

### clem

That webpage is a bit complicated. To put the EM interaction into any QM wave equation
(Schrodinger or Dirac) the substitution del-->del-iqA works.
The transformation of the psi is part of the gauge transformation which works if the form
del-iqA is used.
( gave up on the latex.)

Last edited: Apr 22, 2009