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- Homework Statement
- Use Wick's Theorem to express the string Bose operators ##\hat a_p \hat a_q^{\dagger} \hat a_k^{\dagger}## in terms of normal ordered fields and contractions.

- Relevant Equations
- Wick's Theorem:

$$T[ABC] = N[ABC + \text{all possible contractions of ABC}]$$

This is problem 18.3 from QFT for the gifted amateur. I must admit I'm struggling to interpret what this question is asking. Chapter 18 has applied Wick's theorem to calculate vacuum expectation values etc. But, there is nothing to suggest how it applies to a product of operators.

Does the question simply mean to calculate ##T[\hat a_p \hat a_q^{\dagger} \hat a_k]##?

Any help interpreting the question would be good. Thanks.

Does the question simply mean to calculate ##T[\hat a_p \hat a_q^{\dagger} \hat a_k]##?

Any help interpreting the question would be good. Thanks.