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.
On relations between right and left eigenvectors of nonselfadjoint matrix pencils
On relations of invariants for vector-valued forms.
On rings with zero divisors. Strong -groups
On Roth's pseudo equivalence over rings.
On row-sum majorization
Let be the set of all real or complex matrices. For , we say that is row-sum majorized by (written as ) if , where is the row sum vector of and is the classical majorization on . In the present paper, the structure of all linear operators preserving or strongly preserving row-sum majorization is characterized. Also we consider the concepts of even and circulant majorization on and then find the linear preservers of row-sum majorization of these relations on .
On SAP Fields.
On Schur-Ostrowski type theorems for group majorizations.
On separation of eigenvalues by the permutation group
Let A be an invertible 3 × 3 complex matrix. It is shown that there is a 3 × 3 permutation matrix P such that the product PA has at least two distinct eigenvalues. The nilpotent complex n × n matrices A for which the products PA with all symmetric matrices P have a single spectrum are determined. It is shown that for a n × n complex matrix [...] there exists a permutation matrix P such that the product PA has at least two distinct eigenvalues.
On sequences not enjoying Schur’s property
Here we proved the existence of a closed vector space of sequences - any nonzero element of which does not comply with Schur’s property, that is, it is weakly convergent but not norm convergent. This allows us to find similar algebraic structures in some subsets of functions.
On S-Equivalence of Seifert Matrices.