On polynomials in two projections.
On potentially nilpotent double star sign patterns
A matrix whose entries come from the set is called a sign pattern matrix, or sign pattern. A sign pattern is said to be potentially nilpotent if it has a nilpotent realization. In this paper, the characterization problem for some potentially nilpotent double star sign patterns is discussed. A class of double star sign patterns, denoted by , is introduced. We determine all potentially nilpotent sign patterns in and , and prove that one sign pattern in is potentially stable.
On powers of non-negative matrices
On Powers of Non-Negative Matrices
On products of additive functions (a third approach).
On products of singular elements
On Projections in the Symmetric Power Space.
On projective equivalence of univariate polynomial subspaces.
On properties of quadratic matrices.
On Pseudo-proper Values of a Linear Transformations.
On quadratic forms.
On Quadratic Forms in 3-Manifolds.
On quadratic Hurwitz forms. I
Homogeneous quadratic polynomials in complex variables are investigated and various necessary and sufficient conditions are given for to be nonzero in the set . Conclusions for the theory of multivariable positive real functions are formulated with applications in multivariable electrical network theory.
On R. Chapman's "evil determinant": case p ≡ 1 (mod 4)
For p ≡ 1 (mod 4), we prove the formula (conjectured by R. Chapman) for the determinant of the (p+1)/2 × (p+1)/2 matrix with .
On Rank 4 Quadratic Spaces with Given Arf and Witt Invariants.
On rank one matrices and invariant subspaces.
On rank subtractivity between normal matrices.
On realizability of p-groups as Galois groups
2000 Mathematics Subject Classification: 12F12, 15A66.In this article we survey and examine the realizability of p-groups as Galois groups over arbitrary fields. In particular we consider various cohomological criteria that lead to necessary and sufficient conditions for the realizability of such a group as a Galois group, the embedding problem (i.e., realizability over a given subextension), descriptions of such extensions, automatic realizations among p-groups, and related topics.
On reducing and deflating subspaces of matrices.
On regular elements in an incline.