Poisson structures on the center of the elliptic algebra A_{p,q}(sl(2)_c)
Résumé
It is shown that the elliptic algebra A_{p,q}(sl(2)_c) has a non trivial center at the critical level c=-2, generalizing the result of Reshetikhin and Semenov-Tian-Shansky for trigonometric algebras. A family of Poisson structures indexed by a non-negative integer k is constructed on this center.