- #1
Kevin_spencer2
- 29
- 0
Let's suppose we have a theory with Lagrangian:
\mathcal L_{0} + gV(\phi)
where the L0 is a quadratic Lagrangian in the fields then we could calculate 'exactly' the functional integral:
\int\mathcal D[ \phi ]exp(iS_{0}[\phi]/\hbar+gV(\phi))
where J(x) is a source then we could expand the perturbative exponential:
exp(igV(\phi) \sim a(0)+a(1)g\phi +a(2)g^{2}(\phi)^{2}+...
and apply functional differentiation respect to J(x) to calculate the propagators:
<\phi (x1) \phi(x2)>
then, HOw the singularities or divergences arise?.
\mathcal L_{0} + gV(\phi)
where the L0 is a quadratic Lagrangian in the fields then we could calculate 'exactly' the functional integral:
\int\mathcal D[ \phi ]exp(iS_{0}[\phi]/\hbar+gV(\phi))
where J(x) is a source then we could expand the perturbative exponential:
exp(igV(\phi) \sim a(0)+a(1)g\phi +a(2)g^{2}(\phi)^{2}+...
and apply functional differentiation respect to J(x) to calculate the propagators:
<\phi (x1) \phi(x2)>
then, HOw the singularities or divergences arise?.