楊代數

在表示论中，楊代數（或楊子、Yangian）是一種無限維的霍普夫代数和量子群。這是以楊振寧命名的。俄羅斯物理學家弗拉基米爾·德林費爾德和路德維希·法捷耶夫首先研究了楊子。 若a是半單李代數，Y(a)是无限维的霍普夫代数（跟泛包絡代數有關係）。Y(a)是楊代數。 [ t i j ( p + 1 ) , t k l ( q ) ] − [ t i j ( p ) , t k l ( q + 1 ) ] = − ( t k j ( p ) t i l ( q ) − t k j ( q ) t i l ( p ) ) . {\displaystyle [t_{ij}^{(p+1)},t_{kl}^{(q)}]-[t_{ij}^{(p)},t_{kl}^{(q+1)}]=-(t_{kj}^{(p)}t_{il}^{(q)}-t_{kj}^{(q)}t_{il}^{(p)}).} 若 t i j ( − 1 ) = δ i j {\displaystyle t_{ij}^{(-1)}=\delta _{ij}} T ( z ) = ∑ p ≥ − 1 t i j ( p ) z − p + 1 {\displaystyle T(z)=\sum _{p\geq -1}t_{ij}^{(p)}z^{-p+1}} 若R-矩阵是 R(z)= I+ z-1 P R 12 ( z − w ) T 1 ( z ) T 2 ( w ) = T 2 ( w ) T 1 ( z ) R 12 ( z − w ) . {\displaystyle \displaystyle {R_{12}(z-w)T_{1}(z)T_{2}(w)=T_{2}(w)T_{1}(z)R_{12}(z-w).}} ( Δ ⊗ i d ) T ( z ) = T 12 ( z ) T 13 ( z ) , ( ε ⊗ i d ) T ( z ) = I , ( s ⊗ i d ) T ( z ) = T ( z ) − 1 . {\displaystyle (\Delta \otimes \mathrm {id} )T(z)=T_{12}(z)T_{13}(z),\,\,(\varepsilon \otimes \mathrm {id} )T(z)=I,\,\,(s\otimes \mathrm {id} )T(z)=T(z)^{-1}.} S ( z ) = T ( z ) σ T ( − z ) , {\displaystyle \displaystyle {S(z)=T(z)\sigma T(-z),}} σ ( E i j ) = ( − 1 ) i + j E 2 N − j + 1 , 2 N − i + 1 . {\displaystyle \displaystyle {\sigma (E_{ij})=(-1)^{i+j}E_{2N-j+1,2N-i+1}.}} 杨–巴克斯特方程 超对称杨–米尔斯理论 Chari, Vyjayanthi; Andrew Pressley. A Guide to Quantum Groups. Cambridge, U.K.: Cambridge University Press. 1994. ISBN 0-521-55884-0.  Drinfeld, Vladimir Gershonovich. Алгебры Хопфа и квантовое уравнение Янга-Бакстера [Hopf algebras and the quantum Yang–Baxter equation]. Doklady Akademii Nauk SSSR. 1985, 283 (5): 1060–1064 （俄语）.  Drinfeld, V. G. A new realization of Yangians and of quantum affine algebras. Doklady Akademii Nauk SSSR. 1987, 296 (1): 13–17 （俄语）.  翻译在 Soviet Mathematics - Doklady. 1988, 36 (2): 212–216.  缺少或|title=为空 (帮助) Drinfeld, V. G. Вырожденные аффинные алгебры Гекке и янгианы [Degenerate affine Hecke algebras and Yangians]. Funktsional'nyi Analiz I Ego Prilozheniya. 1986, 20 (1): 69–70. MR 0831053. Zbl 0599.20049 （俄语）.  翻译在 Drinfeld, V. G. Degenerate affine hecke algebras and Yangians. Functional Analysis and Its Applications. 1986, 20 (1): 58–60. doi:10.1007/BF01077318.  Molev, Alexander Ivanovich. Yangians and Classical Lie Algebras. Mathematical Surveys and Monographs. Providence, RI: American Mathematical Society. 2007. ISBN 978-0-8218-4374-1.  Bernard, Denis. An Introduction to Yangian Symmetries. NATO ASI Series. 1993, 310 (5): 39–52. ISBN 978-1-4899-1518-4. arXiv:hep-th/9211133 . doi:10.1007/978-1-4899-1516-0_4.  MacKay, Niall. Introduction to Yangian Symmetry in Integrable Field Theory. International Journal of Modern Physics A. 2005, 20 (30): 7189–7217. Bibcode:2005IJMPA..20.7189M. arXiv:hep-th/0409183 . doi:10.1142/s0217751x05022317.  Drummond, James; Henn, Johannes; Plefka, Jan. Yangian Symmetry of Scattering Amplitudes in N = 4 super Yang-Mills Theory. Journal of High Energy Physics. 2009, 2009 (5): 046. Bibcode:2009JHEP...05..046D. arXiv:0902.2987 . doi:10.1088/1126-6708/2009/05/046.  Beisert, N. (2007). The S-matrix of AdS/CFT and Yangian symmetry. arXiv preprint arXiv:0704.0400. Spill, F. (2009). Weakly coupled N= 4 Super Yang-Mills and N= 6 Chern-Simons theories from u (2| 2) Yangian symmetry. Journal of High Energy Physics, 2009(03), 014, https://arxiv.org/abs/0810.3897 （页面存档备份，存于互联网档案馆）