"Renormalization"의 두 판 사이의 차이

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* Pawlowski, Jan M., Michael M. Scherer, Richard Schmidt, and Sebastian J. Wetzel. “Physics and the Choice of Regulators in Functional Renormalisation Group Flows.” arXiv:1512.03598 [cond-Mat, Physics:hep-Th], December 11, 2015. http://arxiv.org/abs/1512.03598.
 
* Eröncel, Cem, and O. Teoman Turgut. ‘Exact Renormalization Group for Point Interactions’. arXiv:1412.8623 [hep-Th], 30 December 2014. http://arxiv.org/abs/1412.8623.
 
* Eröncel, Cem, and O. Teoman Turgut. ‘Exact Renormalization Group for Point Interactions’. arXiv:1412.8623 [hep-Th], 30 December 2014. http://arxiv.org/abs/1412.8623.
 
* [http://arxiv.org/abs/1008.0129 Renormalization and quantum field theory] R. E. Borcherds, 2010
 
* [http://arxiv.org/abs/1008.0129 Renormalization and quantum field theory] R. E. Borcherds, 2010
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2015년 12월 14일 (월) 02:50 판

renormalization

  • way of pulling out sensible answers from Feynman diagrams that explode
  • there are two parts in the renormalization program
    • regularization - the divergences must be written down in some way so that they can be compared, added and subtracted
    • renormalization proper - the various divergences must be gathered together and extracted from the rest of the calculation
  • set of techniques used to understand a given quantum field theory in a certain energy or length interval
  • easiest to grasp using functional integrals




regularization

  • the values of observable quantities cannot depend on the way we've chosen to take the cutoff (regularize)
  • introducing momentum or distance cutoff so as to render finite the large momentum or short distance limits of correlation functions
  • methods of regularization
    • momentum regularization (modify the propagator by introducing cutoff dependent mass couplings)
    • lattice regulatization (replace $R^d$ by a lattice, uses a small space cutoff)
    • dimensional regularization
  • root of the problem
    • probability of creating particles of colossal energies
    • in terms of Feynman diagrams, the momentum in a loop can run away to infinity
  • dimensional regularization
    • regularization scheme (especially good in QCD)
    • regard the dimension as a continuous quantity
    • coupling constant changes accordingly as the dimension changes continuously
    • we get a new parameter called regularization scheme



QED renormalization



electroweak renormalization

  • spontaneous local symmetry breaking or Higgs mechanism
  • mass term for gauge field is zero in the Lagranaian, but these bosons (W,Z bosons) have mass term. To resolve this, we employ Higgs mechanism



books


expositions

articles