Timeline for Why does the counterterm's propagator have inverse units of the propagator? $\phi^4$-theory
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6 events
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| Mar 2, 2019 at 19:28 | comment | added | Arturo don Juan | I'm talking about Euclideanizing momentum integrals of course, which has one less factor of $-1$ in the mostly plus metric. Also in quantum gravity or supergravity (not necessarily string theory), the mostly plus metric makes more sense - which I don't think you were debating. But you're definitely right about the choice of gauge and regularization scheme being much more impactful, which is why (I think) most people choose Feynman gauge and dimensional regularization when doing loop calculations. | |
| Feb 28, 2019 at 23:02 | comment | added | JamalS | @ArturodonJuan "Actually works in Minkowski"? What? I have done plenty of loop calculations and either signature makes really no difference. Choices of gauge and regularisation are more impactful. | |
| Feb 28, 2019 at 18:42 | comment | added | Arturo don Juan | I've heard that before but honestly I don't think it's true. I'm pretty sure in modern formal QFT research (that actually works in Minkowski, or locally Minkowski, space) the convention is the mostly-plus metric. Probably the people that would use the mostly-minus metric are phenomenologists that aren't actually doing loop calculations, where the other metric is obviously better. | |
| Feb 28, 2019 at 13:34 | comment | added | JamalS | @ArturodonJuan It’s the signature used most in QFT (not counting string theory as QFT). | |
| Feb 26, 2019 at 22:03 | comment | added | Arturo don Juan | For anybody else reading this in the future, both the OP and @JamalS are using the $(+---)$ metric signature, which you can tell by the fact that in the original post the kinetic term is $+\frac{1}{2}(\partial\phi)^2$. The $(\partial_0\phi)^2$ term must be positive. Had they chosen the $(-+++)$ signature, the counterterm would be $-i\left( p^2\delta_Z +\delta_m \right)$. (sorry, that sign was causing me some issues :). | |
| Oct 10, 2017 at 13:58 | history | answered | JamalS | CC BY-SA 3.0 |