"Vertex operator algebra (VOA)"의 두 판 사이의 차이

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<h5>vertex algebra vs VOS</h5>
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<h5>vertex algebra vs VOA</h5>
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* grading on V
  
 
 
 
 

2012년 8월 26일 (일) 19:45 판

definition
  • vertex operator algbera is a quadruple \((V,Y,\mathbf{1},\omega)\) with the following axioms
  • \(V=\bigoplus_{n\in\mathbb{Z}}V_{(n)}\) vector space
  • \(\dim V_{(n)} <\infty\) for \(n\in \mathbb{Z}\)
  • \(\dim V_{(n)}=0\) for \(n<<0\)
  • vertex operator
    \(V\to (\operatorname{End})[[x,x^{-1}]]\)
    \(v\mapsto Y(v,x)=\sum_{n\in \mathbb{Z}}v_{n}x^{-n-1}\)
  • two distinguished vectors \(\mathbf{1}\in V_{(0)}\) and  \(\omega\in V_{(2)}\)

 

 

vertex algebra vs VOA
  • grading on V

 

 

axioms
  •  
    \(u_{n}v=0\) for \(n>>0\)
  • \(Y(\mathbf{1},z)=\operatorname{id}_{V}\)
  • (creation property)
    \(Y(v,z).\mathbf{1}=v+\cdots\)
  • conformal vector
    \(Y(\omega,z)=L(z)=\sum L(n)z^{-n-2}\) satisfies
    \([L_m,L_n]=(m-n)L_{m+n}+\frac{c}{12}(m^3-m)\delta_{m+n}\)
  • \(L(0)v=nv\) for \(n\in\mathbb{Z}\) and \(v\in V_{(n)}\)
  • translation covariance  
    \([D, Y(v,z)]=\sum_{n}[D,V_n]z^{-n-1}=\partial Y(v,z)\)
  • Jacobi identity
    \( $z_0^{-1}\delta(\frac {z_1-z_2}{z_0})Y(u,z_1)Y(v,z_2)-z_0^{-1}\delta(\frac {z_2-z_1}{-z_0})Y(v,z_2)Y(u,z_1)=z_2^{-1}\delta\left(\frac {z_1-z_0}{z_2}\right)Y(Y(u,z_0)v,z_2)$\)

 

 

remark on Jacobi identity
  • Jacobi identity for Lie algebra says
    \((\operatorname{ad} u)(\operatorname{ad} v)-(\operatorname{ad} v)-(\operatorname{ad} u)=(\operatorname{ad}(\operatorname{ad} u) v)\)

 

 

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