All Questions
4
questions
0
votes
1
answer
124
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The definition of the path integral
I still have big conceptual questions about the path integral.
According to (24.6) of the book "QFT for the gifted amateur" from Lancaster & Blundell the path integral is equal to
$$Z =\...
- 9,778
1
vote
0
answers
159
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Connected part of $S$-matrix generating functional
I am currently studying an article by A.Jevicki et. al. (https://doi.org/10.1103/PhysRevD.37.1485) and I am a little confused. They say that the generating functional of the $S$-matrix is related to ...
- 93
2
votes
0
answers
148
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Physical meaning of $\langle 0|S(+\infty,-\infty)|0 \rangle$
when I am reading text book Introduction to Many body physics Piers Coleman 2nd editor, Equation (5.26). I got confused about the meaning of $\langle0|S(+\infty,-\infty)|0\rangle$.
first problem
$|...
- 1,113
13
votes
2
answers
3k
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Physical meaning of partition function in QFT
When we have the generating functional $Z$ for a scalar field
\begin{equation}
Z(J,J^{\dagger}) = \int{D\phi^{\dagger}D\phi \; \exp\left[{\int L+\phi^{\dagger}J(x)+J^{\dagger}(x)}\phi\right]},
\end{...
- 1,336