Let F be a field of characteristic different from 2. It is shown that the problems of classifying (i) local commutative associative algebras over F with zero cube radical, (ii) Lie algebras over F with central commutator subalgebra of dimension 3, and (iii) finite p-groups of exponent p with central commutator subgroup of order p3 are hopeless since each of them contains • the problem of classi...

Let F be a field of characteristic different from 2. It is shown that the problems of classifying (i) local commutative associative algebras over F with zero cube radical, (ii) Lie algebras over F with central commutator subalgebra of dimension 3, and (iii) finite p-groups of exponent p with central commutator subgroup of order p3 are hopeless since each of them contains • the problem of classi...

A novel optimization method is proposed to minimize a convex function subject to bilinear matrix inequality (BMI) constraints. The key idea is to decompose the bilinear mapping as a difference between two positive semidefinite convex mappings. At each iteration of the algorithm the concave part is linearized, leading to a convex subproblem.Applications to various output feedback controller synt...

The main result of this paper is that every nilpotent group of class at most two may be embedded into a central extension of abelian groups, in which the associated cocycle is bilinear (definitions are recalled in Section 1). The result is related to a paper of N.J.S. Hughes (see [2]), in which he establishes a one to one correspondence between the equivalence classes of central extensions of a...

Let A be a symmetric k-algebra over a perfect field k. Külshammer defined for any integer n a mapping ζn on the degree 0 Hochschild cohomology and a mapping κn on the degree 0 Hochschild homology of A as adjoint mappings of the respective p-power mappings with respect to the symmetrizing bilinear form. In an earlier paper it is shown that ζn is invariant under derived equivalences. In the prese...