Is It Known For Sure Infinites In QFT Are Caused Using a Continuum?

  • Context: Graduate 
  • Thread starter Thread starter bhobba
  • Start date Start date
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 2K views
Messages
11,087
Reaction score
3,934
I am reading WHAT IS A QUANTUM FIELD THEORY?" A First Introduction for Mathematicians.

The author states (2.4 Finite versus Continuous Models) that the use of continuity causes the infinities in QFT:

'Mathematicians are trained to think of physical space as R3. But our continuous model of
physical space as R3 is of course an idealization, both at the scale of the very large and
at the scale of the very small. This idealization has proved to be very powerful, but in the
case of Quantum Field Theory, it creates multiple problems, and in particular the infamous
infinities (in the form of diverging integrals).'

I think that, based on what I have read, it is a likely cause, but has it been proven?

It is not an issue in EFT because a cutoff is used to get finite answers. Could a cutoff be looked at as approximating a lattice model?

Thanks
Bill
 
Last edited:
Physics news on Phys.org
There are two kinds on infinities in QFT, UV infinities and IR infinities. UV infinities are due to using a continuum (in both space and time), while IR infinities are due to using infinite extension (in both space and time). And yes, it is known for sure that this is the case.
 
Reply
  • Like
Likes   Reactions: bhobba
I've always been under the impression that the Nielson-Ninomiya theorem precludes the possibility of spacetime having a fundamental lattice-type structure, and that the infinities that appear in QFT a result of using the unphysical bare coupling constants🤔
 
Reply
  • Like
Likes   Reactions: bhobba