New answers tagged greens-functions
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Is there any relevance to these perturbatively defined mode operators in interacting Quantum Field Theories?
Yes the field $\phi_0$ is the standard free field. $\phi_1$ solves $(\Box + m^2 )\phi_1=\phi_0^{3}$ and $\phi_2$ for example is a solution of $(\Box + m^2 )\phi_2=\phi_0^{2}\phi_1$. Graphically $\...
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Form of wide-band limit for the broadening
Typically tunneling matrix elements are characterized not only by the index of state within the "interacting" region $\alpha$, but also the index of the lead from/to which the tunneling ...
- 65k
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Greens Function formalism for the independent boson model
It looks like we are in the interaction picture, and the time dependence of an operator $O$ is defined as
$$
O(t) = e^{iH_0t}\, O \, e^{-iH_0t}.
$$
The perturbation $V$ also has a corresponding $V(t)$ ...
- 438
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Physical interpretation of the Green's function approach to Laplace equation
I will set $\epsilon_0 = 1$ in the following. Recall that to solve the Poisson equation using Green's functions, you compute:
$$
u(x) = \int G(x,y)\rho(y)d^3y
$$
Staring hard at Kirchhoff integral ...
- 15.1k
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Accepted
Pressure field due to line source
Short Answer: I believe the Green's function provides the information you are looking for. Simplify multiply the Green's function by the source amplitude for a point source.
Longer Answer:
The ...
- 2,040
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How is the retarded Green's function modified under the action of time-reversal operator?
The density of states is given by the imaginary part of the retarded Green's function,
$$
N(\vec r, \omega) = \frac{1}{\pi} \text{Im}[{\text{tr}}[G^R(\vec r, \vec r, \omega)]];,$$
where $$G^R(\vec r, \...
- 23.3k
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How is the retarded Green's function modified under the action of time-reversal operator?
The retarded and advanced Green functions are interchanged under time reversal. It isn't the theory itself that breaks time reversal symmetry, it's the definition of the retarded (or advanced) ...
- 3,749
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Iterative Greens function calculation
The solution to the Dyson equation can be approximated iteratively for weak perturbations $V$: $G\approx G_0(1 + VG_0(1 + VG_0(1 + \dots)))$, etc..
If you are interested in Hartree-Fock states, you ...
- 3,749
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