N. Vandenhijligenberg et R. Martini, DIFFERENTIAL HOPF ALGEBRA STRUCTURES ON THE UNIVERSAL ENVELOPING ALGEBRA OF A LIE-ALGEBRA, Journal of mathematical physics, 37(1), 1996, pp. 524-532
We discuss a method to construct a De Rham complex (differential algeb
ra) of Poincare-Birkhoff-Witt type on the universal enveloping algebra
of a Lie algebra g. We determine the cases in which this gives rise t
o a differential Hopf algebra that naturally extends the Hopf algebra
structure of U(g) The construction of such differential structures is
interpreted in terms of color Lie superalgebras. (C) 1996 American Ins
titute of Physics.