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Imagine a QFT with some particle content. Some of these fields will be massless and some massive. For simplicity, consider a massles scalar field and a massive scalar field with mass $M$. If we are working at some energy $E\ll M$, we won't see the massive field (as happened with the Higgs before LHC, for example). This is the IR CFT. Why IR? Because we ...


0

I think that this nomenclature has nothing to do with the regulators. "UV CFT" and "IR CFT" actually refers to the end point of the RG flow which is triggered by a relevant operator that perturbs an UV fixed point, and it ends (barring certain non-unitary QFT) into a fixed point at lower energy scales, hence the name IR.


1

Since you found the critical point via numerical simulations, you probably have little analytical insight into its properties. This makes it hard to extract the central charge, because it often appears in expressions combined with speed of sound or other quantities (e.g. in the free energy for a 2d CFT). So you need to find a universal quantity, easily ...


-2

Well, theoretical suggestions are as many;  but lab techniques suggest for scaled electroscopes to do as such. There also are technical issues Measuring the q charge - contacting method 1) Sure one has to contact the "point" charge with the top head of the electroscope. 2) The scale has to agree with the physical systems of measurements, SI or else. ...


2

There are a few different ingredients going into this: Firstly, the (holomorphic) current generating the infinitesimal conformal transformation $\delta z=\epsilon v(z)$ is $j(z)=i v(z) T(z)$ (there's a similar antiholomorphic one too). The general Ward identity (at $z=0$) for this current gives $$ \frac{1}{i\epsilon}\delta\mathcal A(0,0)=Res_{z\rightarrow ...



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