1 | initial version |
Symbolic functions, as created via function('V')(phi)
, accept only symbolic expressions (i.e. elements of the Symbolic Ring) for their arguments. Hence the error message that you get. To derive the equations of motion, I would advise to introduce, in addition to the scalar field phi
, a symbolic expression, phi0
say, that will represent the scalar field as the argument of the potential V
:
phi0 = var('phi0', latex_name=r'\phi')
V_phi = function('V')(phi0)