The Potential Derivative

The equations of motion for the fields all involve the term ${\partial V \over \partial f}$. When these equations are derived in program variables in section 6.1 this term simply becomes ${\partial V_{pr} \over \partial f_{pr}}$. So once you have written down the program potential all you have to do is take its derivative. For the TWOFLDLAMBDA model this gives

$${\partial V_{pr} \over \partial \phi_{pr}} = \left(\phi_{pr}... ...\chi_{pr}^2\right) \phi_{pr} \qquad\mbox{(TWOFLDLAMBDA model)}$$ (4.12)

$${\partial V_{pr} \over \partial \chi_{pr}} = gl \phi_{pr}^2 \chi_{pr}. \qquad\mbox{(TWOFLDLAMBDA model)}$$ (4.13)