Gw. Delius et Md. Gould, QUANTUM LIE-ALGEBRAS, THEIR EXISTENCE, UNIQUENESS AND Q-ANTISYMMETRY, Communications in Mathematical Physics, 185(3), 1997, pp. 709-722
Quantum Lie algebras are generalizations of Lie algebras which have th
e quantum parameter h built into their structure. They have been defin
ed concretely as certain submodules L-h(g) of the quantized enveloping
algebras U-h(g). On them the quantum Lie product is given by the quan
tum adjoint action. Here we define for any finite-dimensional simple c
omplex Lie algebra g an abstract quantum Lie algebra g(h) independent
of any concrete realization. Its h-dependent structure constants are g
iven in terms of inverse quantum Clebsch-Gordan coefficients. We then
show that all concrete quantum Lie algebras L-h(g) are isomorphic to a
n abstract quantum Lie algebra g(h). In this way we prove two importan
t properties of quantum Lie algebras: 1) all quantum Lie algebras L-h(
g) associated to the same g are isomorphic, 2) the quantum Lie product
of any Ch(B) is q-antisymmetric. We also describe a construction of L
-h(g) which establishes their existence.