Timeline for What does it mean to integrate out fields from a theory?
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 2, 2021 at 4:16 | comment | added | Luboš Motl | Dear Gsuer, you may search for effective field theory-theories at Amazon.com amazon.com/s?k=Effective+field+theory&tag=lubosmotlsref-20 But if I were picking a modern textbook of QFT with the effective field theory methods, going from the beginning to what you need, I could recommend the new textbook of Matthew Schwartz (whom I remember when he was our Harvard student) amazon.com/Quantum-Field-Theory-Standard-Model/dp/1107034736/… See also schwartzqft.fas.harvard.edu | |
| Sep 1, 2021 at 13:03 | comment | added | user242231 | Hey @LubošMotl would you be able to provide some references for introduction to effective field theories and integrating out heavy fields? | |
| Apr 15, 2013 at 18:05 | comment | added | Luboš Motl | Hi @user15766, yes, at least when your rule (and the word "solved") is correctly extrapolated to higher orders. It is indeed a sort of a Born-Oppenheimer approximation in which the light (=slow) degrees of freedom are fixed and the heavy part of the theory is "solved". In practice, the calculation of the effective action leads to the evaluation of all the diagrams with at least one "heavy" propagator... In the context of the renormalization group, we also want to "integrate out" only a part of the field modes, those with energies between $E$ and $E+dE$. | |
| Apr 15, 2013 at 15:14 | comment | added | Siraj R Khan | Thank you for the clear and detailed response, it's a huge help! So are you saying we solve the heavy particle part of the amplitude for each value of the light field, and when this is done for every value of the light field we have an expression that depends only on which value of the light field we choose? Sorry, I just want to make sure I definitely understand the general procedure. | |
| Apr 15, 2013 at 15:03 | vote | accept | Siraj R Khan | ||
| Apr 15, 2013 at 15:00 | history | edited | Luboš Motl | CC BY-SA 3.0 |
added 206 characters in body
|
| Apr 15, 2013 at 14:54 | history | answered | Luboš Motl | CC BY-SA 3.0 |