- #1
QFT1995
- 30
- 1
- Homework Statement
- Compute the following
$$\mathcal{T} \langle {0}| \prod_i^Ne^{\imath \beta_i \phi(x_i)} |0 \rangle$$ without contractions at the same point
- Relevant Equations
- Wick's theorem
If I'm computing
$$\mathcal{T} \langle 0 | \prod_i^Ne^{\imath \beta_i \phi(x_i)} | 0\rangle $$
where the contractions at the same spacetime point are ignored, can I simply insert a complete set of states (product now outside of expression) between each exponential to give
$$\mathcal{T} \prod_i^N \langle 0 |e^{\imath \beta_i \phi(x_i)} | 0\rangle$$
and then the only terms not contributing to contractions at the same spacetime point is the term 1 in the exponential which gives
$$\mathcal{T} \prod_i^N\langle 0 |1 | 0\rangle = 1$$
since
$$ \langle 0 | 0\rangle=1$$
or is this wrong?
$$\mathcal{T} \langle 0 | \prod_i^Ne^{\imath \beta_i \phi(x_i)} | 0\rangle $$
where the contractions at the same spacetime point are ignored, can I simply insert a complete set of states (product now outside of expression) between each exponential to give
$$\mathcal{T} \prod_i^N \langle 0 |e^{\imath \beta_i \phi(x_i)} | 0\rangle$$
and then the only terms not contributing to contractions at the same spacetime point is the term 1 in the exponential which gives
$$\mathcal{T} \prod_i^N\langle 0 |1 | 0\rangle = 1$$
since
$$ \langle 0 | 0\rangle=1$$
or is this wrong?