On certain current algebras related to finite-zone integration.

*(English)*Zbl 1196.17022
Buchstaber, V. M. (ed.) et al., Geometry, topology, and mathematical physics. S. P. Novikov’s seminar: 2006–2007. Selected papers of the seminar, Moscow, Russia, 2006–2007. Dedicated to S. P. Novikov on the occasion of his 70th birthday. Providence, RI: American Mathematical Society (AMS) (ISBN 978-0-8218-4674-2/hbk). Translations. Series 2. American Mathematical Society 224. Advances in the Mathematical Sciences 61, 271-284 (2008).

Lax operator algebras are infinite-dimensional Lie algebras of current type which are associated to higher genus Riemann surfaces with marked points. They were introduced by Krichever and Sheinman and are examples of almost-graded Lie algebras. By M. Schlichenmaier and O. K. Sheinman in [Russ. Math. Surv. 63, No. 4, 727–766 (2008); translation from Usp. Mat. Nauk 63, No. 4, 131–172 (2008; Zbl 1204.17016)] almost-graded central extensions of these algebras were studied and classified. The article under review gives the definition of the Lax operator algebras associated to the finite-dimensional Lie algebras for \(g\) one of the algebras \(\text{gl}(n), \text{sl}(n), \text{so}(n), \text{sp}(2n)\). The classification results of the above mentioned article on almost-graded central extensions are reviewed. As in the classical current algebra case there is essentially only one nontrivial central extension if the finite-dimensional algebra is simple. Lax operator algebras are related to Lax operators on Riemann surfaces. In the article also \(g\)-valued Lax equations and their corresponding phase spaces are discussed. Certain properties are shown. In particular their consistency is checked.

For the entire collection see [Zbl 1143.00004].

For the entire collection see [Zbl 1143.00004].

Reviewer: Martin Schlichenmaier (Luxembourg)

##### MSC:

17B67 | Kac-Moody (super)algebras; extended affine Lie algebras; toroidal Lie algebras |

17B68 | Virasoro and related algebras |

22E67 | Loop groups and related constructions, group-theoretic treatment |

14H60 | Vector bundles on curves and their moduli |

81R10 | Infinite-dimensional groups and algebras motivated by physics, including Virasoro, Kac-Moody, \(W\)-algebras and other current algebras and their representations |

30F30 | Differentials on Riemann surfaces |

14H10 | Families, moduli of curves (algebraic) |

14H15 | Families, moduli of curves (analytic) |

14H55 | Riemann surfaces; Weierstrass points; gap sequences |

81T40 | Two-dimensional field theories, conformal field theories, etc. in quantum mechanics |

17B66 | Lie algebras of vector fields and related (super) algebras |