How is time treated differently in QFT versus relativistic quantum mechanics?

[Tio Barnabe]

I'm starting this thread because @PeterDonis suggested in the other thread that time is treated diferently in quantum field theory and relativistic quantum mechanics/ ordinary quantum mechanics.

I'd like to know specifically how is it treated in QFT and in relativistic Quantum Mechanics. Of course, I could look at a book on the subject, but for the moment I'm interested on this specific topic only, so I'm not going to read a entire book for now.

 

[PeterDonis]

I'd like to know specifically how is it treated in QFT and in relativistic Quantum Mechanics.

It's one of the four dimensions of spacetime, just like in classical relativity.

Of course, I could look at a book on the subject, but for the moment I'm interested on this specific topic only, so I'm not going to read a entire book for now.

Unfortunately, beyond what I just said above, you will need to take the time to work through a book if you want to understand the role that time plays in QFT/relativistic QM.

 

[Tio Barnabe]

It's one of the four dimensions of spacetime, just like in classical relativity.

That's in QFT as well as in relativistic QM? Or just in QFT?

 

[PeterDonis]

That's in QFT as well as in relativistic QM?

QFT is relativistic QM. There is no other theory of relativistic QM that I am aware of.

(Even if there were, to be relativistic it would have to treat time the way time is treated in relativity, which is what I described.)