Some results on the group inverse for block matrices over skew fields.
Some sharp inequalities for Dirac type operators.
Some stochastic comparison results for series and parallel systems with heterogeneous Pareto type components
We focus on stochastic comparisons of lifetimes of series and parallel systems consisting of independent and heterogeneous new Pareto type components. Sufficient conditions involving majorization type partial orders are provided to obtain stochastic comparisons in terms of various magnitude and dispersive orderings which include usual stochastic order, hazard rate order, dispersive order and right spread order. The usual stochastic order of lifetimes of series systems with possibly different scale...
Some subpolytopes of the Birkhoff polytope.
Some theoretical results derived from polynomial numerical hulls of Jordan blocks.
Some trigonometric identities involving Fibonacci and Lucas numbers.
Some variations on the concept of the c-numerical range
SomeRremarks on a Combinatorial Problem
Sous-groupes distingues du groupe unitaire et du groupe général linéaire d'un espace de Hilbert quaternionien.
Sous-groupes distingués du groupe unitaire et du groupe général linéaire d'un espace de Hilbert
Spaces of constant rank matrices over .
Spaces of rank-2 matrices over GF(2).
Sparse recovery with pre-Gaussian random matrices
For an m × N underdetermined system of linear equations with independent pre-Gaussian random coefficients satisfying simple moment conditions, it is proved that the s-sparse solutions of the system can be found by ℓ₁-minimization under the optimal condition m ≥ csln(eN/s). The main ingredient of the proof is a variation of a classical Restricted Isometry Property, where the inner norm becomes the ℓ₁-norm and the outer norm depends on probability distributions.
Special forms of generalized inverses of row block matrices.
Special Similarity Transformations in Connection with the Quadrant Interlocking Factorisation Techniques
Specialization of quadratic and symmetric, bilinear forms, and a norm theorem
Spectra of expansion graphs.
Spectra of weighted compound graphs of generalized Bethe trees.
Spectra of weighted rooted graphs having prescribed subgraphs at some levels.
Spectral approximation for Segal-Bargmann space Toeplitz operators
Let A stand for a Toeplitz operator with a continuous symbol on the Bergman space of the polydisk or on the Segal-Bargmann space over . Even in the case N = 1, the spectrum Λ(A) of A is available only in a few very special situations. One approach to gaining information about this spectrum is based on replacing A by a large “finite section”, that is, by the compression of A to the linear span of the monomials . Unfortunately, in general the spectrum of does not mimic the spectrum of A as...