Lagrangians and Observables, an invitation to renormalization - QFT II, Part 1

[@lanimulrepus]

Good start...

[@jonatanpaschoal7362]

Parabéns professor pelo trabalho.👏🏾

[@Mireladias8]

Muito bom! Parabéns!

[@jacobvandijk6525]

In my opinion, QFT is a good test of one's intelligence. Has it anything to do with reality?

[@Achrononmaster]

Computes electron magnetic moments and a few million scattering amplitudes observable at places like SLAC, Fermilab and CERN. But...yeah none of that is eliminating poverty and suffering so... not the _real_ real world.

[@jacobvandijk6525]

@@Achrononmaster Hmm, you give my question a interesting twist: Is particle physics useful in general? In my opinion, no. CERN, NASA, etc. are modern day Manhattan Projects. They serve predominantly a political goal. But the question I had in mind was: Is particle physics successful? Of course, at CERN, etc. they say "yes". But their results come from indirect detection and statistical interpretation. Increasing collider-energies won't bring us any closer to reality. It's like bridging an infinite distance by taking a few steps forwards (with even bigger uncertainties in evaluating detection-results).

[@dukeyin1111]

it is hard to find jobs outside of academia if you want pure QFT related professions. But imo it was fun to learn, and the renomalization group chapter is actually applicable in many other areas.

[@jacobvandijk6525]

@@dukeyin1111 Of course, it is hard to find a job outside the academic world. The practical use of QFT (of importance in the real world) is almost non-existent. QFT is a nice toy for theoretical physicists to work with in their own comfort zone. The funny thing is that they keep telling each other it is important, haha. But nobody else does.

[@dukeyin1111]

@@jacobvandijk6525 Outside of particle physics, I think non-relativistic QFTs are pretty common at describing phases of exotic matters. Some experimentally found, some are not.