设p≠1为任意取定的正整数.q≠1为p次本原单位根.再设Γ1=(pZ)^2\{(0.0)),Γ2=Z^2\(pZ)^2.记B=spanc{Lm.n|(m,n)∈Γ1UΓ2}为量子环面Cq[x^±1,y±1]上的斜导子李代数,其中,基元满足的李关系为:当(m,n),(r,s)∈Γ2时,[Lm,n,Lr,s]=(qnr-qms)Lm+r,n+s;否则[Lm,n,Lr,s]=(nr—ms)Lm+r,n+s.本文给出了B的一个标准不变对称双线性型以,并通过计算得到,李代数B的不变对称双线性型都是φt的常数倍.作者进一步证明了斜导子李代数B的系数在一维平凡表示C中的Leibniz二上同调群和它的二上同调群相同,即有HL^2(B,C)=H^2(B,C).
Let p≠ 1 be a positive integer, and q≠ 1 be a p-th primitive root of unity. Let Γ1=(pZ)^2/{(0.0)),Γ2=Z^2/(pZ)^2.Denote B= spanc B=spanc{Lm.n|(m,n)∈Γ1UΓ2} the skew derivation Lie algebra over the quantum torus Cq[x^±1,y±1]. The Lie bracket is given by[Lm,n,Lr,s]=(nr-ms)Lm+r,n+s if (m,n),(r,s)∈Γ2 ,and[Lm,n,Lr,s]=(nr-ms)Lm+r,n+s, in other cases. In this paper,the author first gave a standard invariant symmetric bilinear form φ1 of B,and then obtained that any invariant symmetric bilinear form of B is a multiple of φ1. In section two,the author proved that the Leibniz second cohomology group of B with coefficients in the 1-dimensional trivial representation C is equal to the second cohomology group of B,i. e. , HL^2 (B, C)= H^2 (B,C).