〈 Berger | Dillon 〉

Of that list correlation functions are the most fundamental

More fundamentally would be the invariant matrix element for a given process, it essentially decouples all of the quantum stuff from the SR and all of the things on your list are functions of these

Let’s try to keep a single thread going this time lmao

The ontology of QFT in my mind is one of the most difficult possible tasks.. a “hard problem” if you will, to abuse Daniel Chalmers phrase

It requires at its heart understanding wtf the QFT formalism is describing

There’s a great PSE post on this.. take the field operator φ³.. as a field operator it’s not even clear what this even means

Lmao yeah it’s pretty hilarious to see the PSE answer questions about physical significance of X, where we have the most abstract mathematical formalisms as far divorced from human experience as possible

Though if I’m not mistaken the S matrix and correlation functions and the invariant matrix element are essentially the same thing with different names