Am. Vershik et Bb. Shoikhet, Graded Lie algebras whose Cartan subalgebra is the algebra of polynomials in one variable, THEOR MATH, 123(2), 2000, pp. 701-707
We define a class of infinite-dimensional Lie algebras that generalize the
universal enveloping algebra of the algebra sl(2, C) regarded as a Lie alge
bra. These algebras are a special case of Z-graded Lie algebras with a. con
tinuous root system, namely, their Cartan subalgebra is the algebra of poly
nomials in one variable. The continuous limit of these algebras defines new
Poisson brackets on algebraic surfaces.