1-loop renormalization of a scalar theory in QFT - part 2
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- Опубліковано 29 вер 2024
- In this video we renormalize the theory for a scalar field with quartic interactions.
The video is an excerpt from the course on Advanced Quantum Field Theory. In the course, I try to give more insights with respect to what you find in Professor David Skinner's notes (which inspired the course, as well as many of the videos therein).
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At 8:41 the propagator is in the form of 1/(k^2 + m^2 - Π(k^2)), where we already use the physical mass m^2 alongside Π(k^2)?
so its not that the physical mass comes from the combination of bare mass m0^2 and the 1PI diagrams Π(k^2)?
Taking into account quantum corrections, m^2 does not necessarily have to be viewed as the experimentally measured mass (squared), unless you choose the counterterms that arise from the action appropriately, so as to cancel the quantum corrections. These counterterms represent our freedom to adjust the couplings in the original action (the theory of renormalization tells you this).
The Lagrangian parameter "m" may or may not correspond to the experimental mass.
Thinking about this, can the statement "the masses and couplings that emerge in the final result are the finite values obtained in experiments" (renormalization of the theory) be thought of as an extra postulate to the framework of QFT?
I think I get what you mean, and your question makes sense. But I would not consider the statement (which is the essence of renormalization itself) an extra postulate added to the framework of QFT; rather, I view it (renormalization) as a systematic mathematical procedure used to make sense of the theory when infinities appear in intermediate calculations. It is an essential part of the theoretical framework, allowing physicists to connect QFT with experimental observations in a consistent and meaningful way.
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