Regular linear matrix pencils A − E∂ ∈ K[∂], where K = Q, R or C, and the associated differential algebraic equation (DAE) Eẋ = Ax are studied. The Wong sequences of subspaces are investigate and invoked to decompose the Kn into V⊕W, where any bases of the linear spaces V and W transform the matrix pencil into the Quasi-Weierstraß form. The Quasi-Weierstraß form of the matrix pencil decouples t...

Let E/k be a cubic field extension and J a simple exceptional Jordan algebra of degree 3 over k. Then £ is a reducing field of J if and only if E is isomorphic to a (maximal) subfield of some isotope of /. If k has characteristic not 2 or 3 and contains the third roots of unity then every simple exceptional Jordan division algebra of degree 3 over k contains a cyclic cubic subfield. Exceptional...

Spectral indices from models of inflation which incorporate a Generalized Einstein Theory (GET) gravity sector are calculated to first order in a slow-roll expansion. By quantizing a suitably-generalized measure of the intrinsic curvature perturbation, the spectral indices as calculated in the Jordan frame now match those as calculated following a conformal transformation, in the Einstein frame...

We investigate the convergence of GMRES for an n by n Jordan block J . For each k that divides n we derive the exact form of the kth ideal GMRES polynomial and prove the equality max ‖v‖=1 min p∈πk ‖p(J)v‖ = min p∈πk max ‖v‖=1 ‖p(J)v‖, where πk denotes the set of polynomials of degree at most k and with value one at the origin, and ‖ · ‖ denotes the Euclidean norm. In other words, we show that ...

Abstract We recall two formulas, due to C. Jordan, for the successive derivatives of functions with an exponential or logarithmic inner function. We apply them to get addition formulas for the Stirling numbers of the second kind and for the Stirling numbers of the first kind. Then we show how one can obtain, in a simple way, explicit formulas for the generalized Euler polynomials, generalized E...

Morphological changes of S. mutans NCTC 10449S associated with growth in modified Jordan medium and FMC medium (Terleckyj et al., Infect. Immun. 11:649-655, 1975) were studied by scanning electron microscopy. The cells were bacillary in Jordan medium, but coccoid and of unequal size in FMC. Transfer of the cells from Jordan medium to FMC and vice versa reversed their shapes, as did salt exchang...

The rank-k numerical range has a close connection to the construction of quantum error correction code for a noisy quantum channel. For noisy quantum channel, a quantum error correcting code of dimension k exists if and only if the associated joint rank-k numerical range is non-empty. In this paper the notion of joint rank-k numerical range is generalized and some statements of [2011, Generaliz...

Frames play significant role in various areas of science and engineering. Motivated by the work of Chander Shekhar, S. K. Kaushik and Abas Askarizadeh, Mohammad Ali Dehghan, we introduce the concepts of $K$-frames for $B(mathcal{H, K})$ and  we establish some result. Also, we consider the relationships between $K$-Frames and $K$-Operator Frames for $B(mathcal{H})$.

We derive a closed form for the Jordan decomposition of companion matrices including properties of generalized eigenvectors. As a consequence, we provide a formula for the inverse of confluent Vandermonde matrices and results on sensitivity of multiple roots of polynomials.

We present necessary and sufficient conditions for the reducibility of a self-adjoint linear relation in Krein space. Then generalized Nevanlinna function Q represented by A Pontryagin space can be decomposed means reducing subspaces A. The sum two functions $$ {Q}_i\in {N}_{\kappa_i}\left(\mathcal{H}\right) , i = 1, 2, minimally triplets \left({\mathcal{K}}_i,{A}_i,{\Gamma}_i\right) is also st...