Gauge theory

수학노트
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introduction


meaning of the gague invariance

  • gauge = measure
  • gauge invariance = measurement에 있어서의 invariance를 말함
  • Lagrangian should be gauge invariant.


gauge symmetry and measurement

  • symmetry implies the existence of something unmeasurable.
  • phase is one example


gauge field

  • a gauge field is defined as a four-vector field with the freedom of gauge transformation, and it corresponds to massless particlas of spin one
  • one example is the electromagnetic field


gauge field tensor

  • electromagnetic field tensor <math>F_{\mu\nu} = \partial_\mu A_\nu - \partial_\nu A_\mu \,\!</math>
  • general gauge fields tensor <math>G_{\mu\nu}^{a}=\partial_{\mu}W_{\nu}^{a}-\partial_{\nu}W_{\mu}^{a}-gw^{abc}W_{\mu}^{b}W_{\nu}^{c}</math>



examples of renormalizable gauge theory



Abelian gauge theory

  • abelian gauge theory has a duality



Non-Abelian gauge theory



differential geometry formulation

  • manifold <math>\mathbb R^{1,3}</math> and having a vector bundle gives a connection
  • connection <math>A</math> = special kind of 1-form
  • <math>dA</math> = 2-form which measures the electromagnetic charge
  • Then the Chern class measures the magnetic charge.



Principal G-bundle




3d Chern-Simons theory

  • 3d Chern-Simons theory on <math>\Sigma\times \mathbb R^{1}</math> with gauge choice <math>A_0=0</math> is the moduli space of flat connections on <math>\Sigma</math>.
  • analogy with class field theory
  • replace <math>\Sigma</math> by <math>spec O_K</math>
  • then flat connection on <math>spec O_K</math> is given by Homomorphism group the absolute Galois group Gal(\barQ/K)->U(1)
  • Now from An's article,



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related items



encyclopedia



books

  • The Geometry of Physics: An Introduction
  • An elementary primer for gauge theory
  • 찾아볼 수학책



expositions

articles

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Spacy 패턴 목록

  • [{'LOWER': 'gauge'}, {'LEMMA': 'theory'}]
  • [{'LOWER': 'gauge'}, {'LEMMA': 'symmetry'}]