What Causes Divergences in QFT?

  • Context: Graduate 
  • Thread starter Thread starter eljose
  • Start date Start date
  • Tags Tags
    Phsyics
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 2K views
eljose
Messages
484
Reaction score
0
more than a proper topic this is a question...my question is if all the divergences that appear in QFT are due to integrals in the form:

[tex]\int_{0}^{\infty}dkk^{m}[/tex]

with m=-1 (logarithmic),0,1,2,3,4,5,...

if not i think that for any other divergences you could express them as:

[tex]\int_{0}^{\infty}dkF(k)= \sum_{r=0}^{\infty}a(r)\int_{0}^{\infty}dkk^{r}[/tex]

r=0,1,2,3,4,5,... and a(r) the coefficients of the series expansion for the function F(k) of course K here is the "momentum" modulus [tex]p=\hbar{k}[/tex]
 
Physics news on Phys.org
Roughly speaking yes, all integrals are of this form. Though there is the issue of overlapping divergences and subgraphs, e.g. a single loop integral might result in a logarithmically divergent term that contains the integration variable of another loop integral.