Double-Bosonisation and the Construction of {}
arXiv:q-alg/9511001
Abstract
We introduce a quasitriangular Hopf algebra or `quantum group' , the {\em double-bosonisation}, associated to every braided group in the category of -modules over a quasitriangular Hopf algebra , such that appears as the `positive root space', as the `Cartan subalgebra' and the dual braided group as the `negative root space' of . The choice recovers Lusztig's construction of , where is Lusztig's algebra associated to a Cartan datum; other choices give more novel quantum groups. As an application, our construction provides a canonical way of building up quantum groups from smaller ones by repeatedly extending their positive and negative root spaces by linear braided groups; we explicitly construct from by this method, extending it by the quantum-braided plane . We provide a fundamental representation of in . A projection from the quantum double, a theory of double biproducts and a Tannaka-Krein reconstruction point of view are also provided.
LATEX 57 pages and epsf figures