Reputation
1,101
Next privilege 2,000 Rep.
Edit questions and answers
Badges
8 18
Newest
 Yearling
Impact
~19k people reached

  • 0 posts edited
  • 0 helpful flags
  • 33 votes cast
Jan
21
awarded  Yearling
Oct
7
comment How can perturbativity survive renormalization?
But, being more specific: when you do perturbation you have to expand $Exp(- i S_{I}- i S_{CT})$ (S are the action of the interaction and of the counterterms), and pick the first terms. I understand doing that for $S_{I}$ but not $S_{CT}$. It seems that this step in the calculation is invalid. Of course the infinities will cancel but that seems to me like "holding" a limit - it seems like the order in which you take limits ($\lambda$ small vs. huge regulator) make a difference in the result
Oct
7
comment How can perturbativity survive renormalization?
The question is more specific than "explain me renormalization". Also, if the infinity is just "pushed to the next order", how can you explain truncating the series?
Oct
6
asked How can perturbativity survive renormalization?
Sep
3
comment Ward Takahashi identities from Z invariance
Just be sure: so I'm right about this commutation business being all wrong? Also: is the link I posted to the book itself (on Google books) working?
Sep
2
revised Ward Takahashi identities from Z invariance
added 130 characters in body
Sep
2
accepted What´s the importance of the normalization of the Kinetic term?
Sep
2
comment What´s the importance of the normalization of the Kinetic term?
Thanks, I'll have to check that keeping $\hbar$ around. I included some comments in the question.
Sep
2
comment What´s the importance of the normalization of the Kinetic term?
Included my take on this on the question. Please let me know if I got it wrong.
Sep
2
revised What´s the importance of the normalization of the Kinetic term?
Includind answer
Aug
30
comment Ward Takahashi identities from Z invariance
I understand what you are saying, that's what you do when writing supersymmetric models in terms of 2-spinors. But these are usual 4-component Dirac spinors and their sources. I never seen their scalar product defined in any other way than just the sum of the product of their components. In fact this seems to indicate just that.
Aug
30
awarded  Analytical
Aug
30
asked Ward Takahashi identities from Z invariance
Aug
30
revised the sounds of an exploding star
added 4 characters in body
Aug
30
comment What´s the importance of the normalization of the Kinetic term?
Thanks for point out the mistakes - I corrected them in the question. As for your answer: does it have to do with the $\langle p | \phi | 0 \rangle $ that appears when you are building the LSZ formula? I think I got it but I want to be sure before including my conclusion in the question itself. Being more specific: I guess there will be a $\sqrt{2} \langle p | \phi | 0 \rangle $ in the case of ${\cal L}_2$ but I can't see how it appears without doing field redefinitions.
Aug
30
revised What´s the importance of the normalization of the Kinetic term?
Fixed normalization and mass sign
Aug
29
answered Relation between statistical mechanics and quantum field theory
Aug
29
answered the sounds of an exploding star
Aug
29
asked What´s the importance of the normalization of the Kinetic term?
Aug
24
awarded  Commentator