In this paper, we study Leibniz algebras with a non-degenerate Leibniz- symmetric fl-invariant bilinear form B, such a pair （g, B） is called a quadratic Leibniz algebra. Our first result generalizes the notion of double extensions to quadratic Leibniz algebras. This notion was introduced by Medina and Revoy to study quadratic Lie alge- bras. In the second theorem, we give a sufficient condition for a quadratic Leibniz algebra to be a quadratic Leibniz algebra by double extension.
We explicitly compute the first and second cohomology groups of the SchrSdinger algebra S（1） with coefficients in the trivial module and the finite-dimensional irreducible modules. We also show that the first and second cohomology groups of S（1） with coefficients in the universal enveloping algebras U（S（1）） （under the adjoint action） are infinite dimensional.
In this paper, an explicit determinant formula is given for the Verma modules over the Lie algebra W(2, 2). We construct a natural realization of a certain vaccum module for the algebra W(2, 2) via the Weyl vertex algebra. We also describe several results including the irreducibility, characters and the descending filtrations of submodules for the Verma module over the algebra W(2, 2).
In this paper we study the homology and cohomology groups of the super Schrodinger algebra S(1/1)in(1+l)-dimensional spacetime.We explicitly compute the homology groups of S(1/1)with coefficients in the trivial module.Then using duality,we finally obtain the dimensions of the cohomology groups of S(1/1)with coefficients in the trivial module.
In this paper, the extended affine Lie algebra sl2（Cq） is quantized from three different points of view, which produces three non-commutative and non-cocommutative Hopf algebra structures, and yields other three quantizations by an isomorphism of sl2 （Cq） correspondingly. Moreover, two of these quantizations can be restricted to the extended affine Lie algebra sl2（Cq）.
