Questions tagged [renormalization]
This tag is for questions which relates with the renormalization, an ensemble of techniques which serves to treat the infinities which appear in quantum field theory or statistical mechanics. Renormalization procedures are based on the requirement that certain physical quantities (such as the mass and charge of an electron) equal observed (experimental) values.
2,092 questions
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Where do experiments enter the renormalization procedure?
I'm studying the renormalization of scalar quantum field theories ($\lambda\phi^4$ in particular). I'm considering renormalization by counterterms with the old non-Wilsonian interpretation of ...
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-2 votes
0 answers
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Why does wave function renormalization result in a term in front of $(\nabla \phi)^2$?
I have asked previous questions about wavefunction renormalization before (e.g. What exactly is field strength renormalization? or What is the difference between wavefunction renormalization and field ...
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4 votes
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Under what conditions do functional renormalization group (FRG) limit cycles occur in asymptotically safe gravity? [closed]
In the functional-renormalization-group (FRG) formulation of quantum gravity, the effective average action Γₖ evolves with the RG scale k according to the Wetterich equation $$\partial_k \Gamma_k = \...
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2 votes
1 answer
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Two-loop diagrams for the 4-point function in $\phi^4$ theory
My book Peskin & Schroeder says on p. 326 that 0-loop & 1-loop order diagrams are: Also 2-loop order diagrams are listed in eq. (10.51) on p. 338: I have no idea what $s$ means in the last ...
- 101
4 votes
1 answer
153 views
On when $-\lambda \phi^N/N!$ in $D$ dimensions is renormalizable
Question. For which values of $N \geq 2$ and $D \geq 1$, such that $[\lambda] > 0$, $[\phi] < 0$, the scalar field theory $-\lambda \phi^N/N!$ in $D$ dimensions is renormalizable? Why the ...
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QED renomalization: Residue of the fermion propagator [duplicate]
I am trying to understand how one gets the residue of the fermion propagator and what its significance is. I suppose that a distinction between the field in the free theory and in the interacting ...
- 2,010
2 votes
1 answer
201 views
Confusion about the running of the mass
In the Wilsonian picture one can imagine that at the intrinsic scale $Λ$ is where the "true" couplings reside and then by integrating degrees of freedom the couplings get corrected (to the ...
1 vote
1 answer
202 views
Ghost-gluon vertex renormalization constant in QCD
I want to obtain the beta function of QCD. In order to do that, I wrote down the ghost self-energy at one-loop including the required counter term and computed the ghost-field renormalization constant ...
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