New answers tagged vacuum
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Accepted
Why does the imaginary time Euler-Lagrange equation imply the potential goes to zero at infinite imaginary time?
For the shape of the potential $V$ Ref. 1 is apparently referring to Fig. 2, i.e. the potential $V$ is assumed to have classical false vacuum, i.e. a local minimum $V(q_0)=0$ that is metastable, i.e. ...
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How can a non-derivative interaction involve the derivative of a scalar field?
First, just a small terminology note. People normally say "derivative" instead of "4-derivative" to refer to $\partial_\mu$. People might say "4-gradient" if they want to ...
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How can a non-derivative interaction involve the derivative of a scalar field?
The kinetic term does not count as an interaction. Quadratic terms in the Lagrangian are present in the free theory. Terms with three or more instances of the field are interactions. Hence, in the ...
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How can a non-derivative interaction involve the derivative of a scalar field?
If $U(\phi)$ is not a quadratic function, then the higher-order terms (e.g. a $\phi^4$ term) can be interpreted as field self-interactions that don’t involve derivatives.
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Could a single gamma ray photon break the Schwinger limit? If so, at what energy?
Consider an electorn-positron collision, and the subsequent production if photons. It is known that there must be at least two photons produced. This is because momentum must be conserved. In the ...
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Vacuum flucutuations = local entanglement between quantum fields?
By some measures the vacuum state is highly entangled as described by a result in quantum field theory called the Reeh-Schlieder theorem. See Section V of a review of "Quantum Information and ...
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Is it possible to lower the energy of the vacuum?
I agree with what others have said here, QFT should be learned in university, but to actually answer your question: let's say your description of quantum vacuum energy is correct. No, you can't alter ...
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Could cosmic rays induce a vacuum decay in the future?
The usual line of reasoning about vacuum decay treats it as a random phenomenon: there are events where it might be triggered, and since it has not happened yet we get a bound on how likely it is. ...
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Bogoliubov transformation of Bunch-Davies vacuum
Yes, that's exactly the point.
In $H_\alpha$ we have that $|\alpha\rangle$ is a vacuum state, but in $H_0$ it is a multiparticle (thermal) state.
In the same way, in $H_0$ we have that $|0\rangle$ is ...
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