Structured Jordan canonical forms for structured matrices that are Hermitian, skew Hermitian or unitary with respect to indefinite inner products.
Structured low rank approximations of the sylvester resultant matrix for approximate GCDS of Bernstein basis polynomials.
Structured polynomial eigenproblems related to time-delay systems.
Structured tools for structured matrices.
Structures Algebraiques munis, avec des lois de composition generalisees - Generalisations du produit scalaire
Stupeň inverznej krivky v projektívnom priestore Lagrangeových-Sylvestrových polynómov
Su alcuni invarianti numerici associati a sistemi di equazioni lineari in un modulo
Subdeterminants and subgraphs
Subdirect sums of nonsingular -matrices and of their inverses.
Subdominant eigenvalues for stochastic matrices with given column sums.
Subgroups of a finite group whose algebra of invariants is a complete intersection
Subharmonicity in von Neumann algebras
Let ℳ be a von Neumann algebra with unit . Let τ be a faithful, normal, semifinite trace on ℳ. Given x ∈ ℳ, denote by the generalized s-numbers of x, defined by = inf||xe||: e is a projection in ℳ i with ≤ t (t ≥ 0). We prove that, if D is a complex domain and f:D → ℳ is a holomorphic function, then, for each t ≥ 0, is a subharmonic function on D. This generalizes earlier subharmonicity results of White and Aupetit on the singular values of matrices.
Sudoku graphs are integral.
Sufficient Conditions for a Pair of n-Planes to be Area-Minimizing.
Sufficient conditions to be exceptional
A copositive matrix A is said to be exceptional if it is not the sum of a positive semidefinite matrix and a nonnegative matrix. We show that with certain assumptions on A−1, especially on the diagonal entries, we can guarantee that a copositive matrix A is exceptional. We also show that the only 5-by-5 exceptional matrix with a hollow nonnegative inverse is the Horn matrix (up to positive diagonal congruence and permutation similarity).
Sulla caratteristica della jacobiana dei sistemi lineari irriducibili di quadriche
Sulla decomposizione dei tensori
Sulle forme polarizzanti i coefficienti del polinomio caratteristico di una matrice
The multilinear forms, obtained by polarizing the coefficients of the characteristic polynomial of a matrix, are considered. A general relation (formula A) between such forms is proved. It follows in particular a rational expression for the above-mentioned coefficients (formula C), which is in a sense analogous to Newton's formulas, but with the use of the determinant function instead of the trace function.
Sulle maggioranti i numeri caratteristici di una matrice quadrata.
Sulle trasformazioni finite dei gruppi delle rotazioni.