All Questions
Tagged with semiclassical quantum-field-theory
7 questions with no upvoted or accepted answers
4
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What do the authors of the paper mean here exactly by path integral?
First of all, please forgive me if i am asking a dumb question. I don't have a physics background. I was reading this paper by Hawking & Hertog on populating string theory landscape and came ...
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2
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How can we calculate simple quantum tunneling processes from the path integral?
I've been reading through Altland and Simons' Condensed Matter Field Theory, and am confused a bit by their discussion on tunneling and instantons. However I don't quite understand how this relates to ...
- 21
2
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WKB solution in QFT: classical action and particle vs antiparticle case
Consider the theory of a complex scalar field
$$S[\psi, \psi^\dagger] = -\int d^4x \left(\hbar \partial_\mu \psi^\dagger \partial^\mu\psi + \hbar^{-1} m^2 |\psi|^2\right)$$
giving the Klein-Gordon ...
- 781
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Why is the semiclassical approximation of the abelian Chern-Simons theory exact?
I was told that in abelian Chern-Simons theory (say, with a general level matrix $K$), semiclassical approximation is exact because there is no trivalent vertex, which in non-abelian case makes the ...
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Mesons as a two-body problem is semiclassical QCD?
In particle physics and quantum field theory, mesons are interpreted as a system composed of a quark and an anti-quark, and the color charge of both must be at each opposite moment (green/anti-green, ...
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1
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Compatibility of renormalisation with the quantum-classical correspondence principle
We know that Quantum Theories obey the Heisenberg equations of the motion, taking the expected values of which gives us the classical equations.
Also, We replace the mass and coupling parameters of a ...
- 6,676
1
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Path integrals and classical paths obtained via saddle point integration
EDIT: Focussed my question more based on @octonion's comments
Say one is interested in the following action,
$$S[\{\phi_i(x,t), \tilde{\phi_i(x,t)}\}] = \int \mathrm{d}t\mathrm{d}^d x\left(\tilde{\...
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