Self-energy for two correlators

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In summary, the conversation discusses the calculation of the interacting single particle Green function in a model. The Dyson equation is mentioned as a way to calculate this function, and it is shown that the self-energy, denoted by $\Sigma$, is involved in the equation. The question is posed whether the self-energy changes when calculating a correlator, specifically the correlator $g(t-t')=\langle Td(t)^{\dagger}d(t')\rangle$. The speaker's intuition is that the self-energy should not change, but they are unsure. Additionally, it is asked if the Dyson equation can be applied to this correlator, even though it is not the definition of a Green function. The possibility of using perturbation theory
  • #1
gonadas91
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Imagine I want to calculate the INTERACTING single particle Green function in a model:

\begin{eqnarray}
G(t-t')=\langle Td(t)d^{\dagger}(t')\rangle
\end{eqnarray}

We know from Dyson equation that this is:\\
\begin{eqnarray}
G=G_{0} + G_{0}\Sigma G
\end{eqnarray}
Where $\Sigma$ is the self-energy. My question is, if we want to calculate the correlator :\\
\begin{eqnarray}
g(t-t')=\langle Td(t)^{\dagger}d(t')\rangle
\end{eqnarray}
Does the self-energy $\Sigma$ change for this correlator? In my intuition it shouldnt, but maybe I am wrong... Thanks!
 
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  • #2
Oh and by the way I forgot, does Dyson equation apply to this correlator as well ($g(t-t')$)? (Even not being the definition of a Green function, can this infinite series be hold in a correlator like that when we do perturbation theory? )
 

1. What is self-energy for two correlators?

Self-energy for two correlators is a concept in quantum field theory that describes the interaction between two particles, or correlators, as they exchange energy. It is also known as the two-particle irreducible (2PI) effective action.

2. How is self-energy for two correlators calculated?

Self-energy for two correlators is calculated using Feynman diagrams, which represent the possible interactions between the two correlators. The diagrams are then solved using mathematical techniques such as perturbation theory.

3. What is the importance of self-energy for two correlators?

Self-energy for two correlators is important because it helps us understand the behavior of particles in quantum field theory. It allows us to calculate the probability of interactions between particles and make predictions about their behavior.

4. How does self-energy for two correlators affect the properties of particles?

The self-energy for two correlators can affect the properties of particles by changing their mass, charge, and other physical characteristics. It describes how the interactions between particles can affect their observable properties.

5. What are some applications of self-energy for two correlators?

Self-energy for two correlators has many applications in physics, including in the study of phase transitions, particle interactions in high energy physics, and the behavior of condensed matter systems. It is also used in theoretical calculations for predicting the properties of new particles and materials.

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