Questions tagged [effective-field-theory]

Question 1

I am studying the Effective Field Theory for extended objects proposed by Goldberger and Rothstein. This theory studies a binary system in inspiral phase. By means of the virial theorem we get a ...

Question 2

recently I was revisiting the path integral formalism to approach condensed matter systems, and there is a question I've always had which is not yet clear to me. In physics, there are many ways to ...

Question 3

Setup Consider the 5D metric with a single warp factor depending only on the extra coordinate: $$ ds^2 \;=\; e^{2A(\rho)}\,\bar g_{\mu\nu}(x)\,dx^\mu dx^\nu \;+\; d\rho^2 , $$ with signature ((+----))...

Question 4

Consider $SU(2)$ gauge theory with a scalar. Cook up a potential such that this scalar gets a vev $v$. Then, at low energies we get a $U(1)$ gauge theory. Now $U(1)$ has its own scale $\Lambda$, the ...

Question 5

For the cubic gravity with Lagrangian $$ \sqrt{-g} \left(R+\frac{1}{\Lambda^4}R_{\mu \nu}{ }^{\alpha \beta} R_{\alpha \beta}{ }^{\gamma \sigma} R_{\gamma \sigma}{ }^{\mu \nu}\right), $$ where $\Lambda$...

Question 6

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 ...

Question 7

Given a UV-divergent theory, is the $\beta$-function same for both massive and massless case for that theory? A more concrete example would be $\phi^3$ in $d=6$ dimensions. I calculated the $\beta$ ...

Question 8

Quantum electrodynamics is non-renormalizable in more than four dimensions (see Peskin & Schroeder, chapter 10). This would seem to put it on similar footing as gravity for $d>4$ in the sense ...

Question 9

Conventional wisdom regarding RG flow for QFTs (at least at the level of textbooks) states that the renormalization group flows from a UV CFT to an IR CFT, both of which correspond to fixed points of ...

Question 10

I used to think that if a quantum field theory was not perturbatively renormalizable, it could not be defined nonperturbatively too. However, I just found out the possibility of asymptotic safety of a ...

Question 11

Hi :) maybe a stupid question, but I keep getting confused about this so I thought I would ask. I am a student and currently working with conformal field theories. One thing I read repeatedly is that ...

Question 12

From what I understand about Wilsonian RG, one of the key insights involved is that if you start with (say a scalar $\phi^4$) theory on a lattice and wish to define a meaningful continuum limit (which ...

Question 13

Hello while I was studying Wilsonian theory mainly on focusing on $\phi^4$ theory, but I need some clarifications, I mainly followed the Sredniciki (chapter 29) but something does not quite add up ...

Question 14

I had a course on QFT some years ago where renormalization was introduced but not very well motivated. It was basically introduced as a consequence of the divergence arising in the integrals when one ...

Question 15

I'm currently studying the Wilsonian effective theory and I'm a bit confused about relevant/irrelevant/marginal operators. I understood why they are called in this way, in particular that the ...

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Questions tagged [effective-field-theory]

Potential and Radiation gravitons scaling

Effective interactions and screening from Feynman diagrams in condensed matter and interpretations

Dimensional reduction check: R^(5) for ds^2 = e^(2A(rho)) gbar_{mn}(x) dx^m dx^n + d(rho)^2 [closed]

Higgs vs Landau scale

How to derive the field equations for cubic gravity in arXiv:1704.01590?

Confusion about the running of the mass

Beta Function for massive and massless theories for regulating UV divergences

How does string theory handle non-renormalizability of QED in $d>4$?

Can both the UV and IR limits of the RG flow not be fixed points of the flow?

Perturbation theory about a non-trivial fixed point of the renormalization group?

What do we mean when we say that certain QFTs „become“ conformal in IR or UV?

Tuning of bare parameters in RG and the Hierarchy Problem

Wilsonian theory different lagrangians and RGE

Does Wilsonian renormalisation allow to send the UV cutoff to $\infty$?

$\Phi^4$ as a relevant/irrelevant/marginal operator

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