DERIVATIONS OF THE TWO-PARAMETER QUANTIZED ENVELOPING ALGEBRA Ur,s(+) (B-2)
Let r, s be two parameters chosen from (Gamma(*) such that r(m)s(n) = 1 implies m = n = 0. We compute the derivations of the two-parameter quantized enveloping algebra U-r,s(+)(B-2) and calculate its first degree Hochschild cohomology group. We further determine the group of algebra automorphisms for the two-parameter Hopf algebra U-r,U-s >=(0)(B-2). As a result, we determine the group of Hopf algebra automorphisms for U-r,U-s >=(0)(B-2).
derivations hochschild cohomology algebra automorphisms hopf algebra automorphisms