Given a sequence of real or complex numbers, we construct a sequence of nested, symmetric matrices. We determine the LU- and QR-factorizations, the determinant and the principal minors for such a matrix. When the sequence is real, positive and strictly increasing, the matrices are strictly positive, inverse M-matrices with symmetric, irreducible, tridiagonal inverses., Jeffrey L. Stuart., and Obsahuje seznam literatury
The aim of this paper is to establish an existence and uniqueness result for a class of the set functional differential equations of neutral type \left\{ {\begin{array}{*{20}c} {D_H X(t) = F(t,X_t ,D_H X_t ),} // {\left. X \right|_{\left[ { - r,0} \right]} = \Psi ,} // \end{array} } \right. where F: [0, b]× C_{0}x L_{0}^{1}\rightarrow K_{c}(E)) is a given function, Kc(E) is the family of all nonempty compact and convex subsets of a separable Banach space E, C0 denotes the space of all continuous set-valued functions X from [−r, 0] into Kc(E), L_{0}^{1} is the space of all integrally bounded set-valued functions X: [−r, 0] → Kc(E), Ψ \in C_{0} and D_{H} is the Hukuhara derivative. The continuous dependence of solutions on initial data and parameters is also studied., Umber Abbas, Vasile Lupulescu, Donald O’Regan, Awais Younus., and Obsahuje seznam literatury
Let u be a holomorphic function and φ a holomorphic self-map of the open unit disk D in the complex plane. We provide new characterizations for the boundedness of the weighted composition operators uCφ from Zygmund type spaces to Bloch type spaces in D in terms of u, φ, their derivatives, and φn, the n-th power of φ. Moreover, we obtain some similar estimates for the essential norms of the operators uCφ, from which sufficient and necessary conditions of compactness of uCφ follows immediately., Xin-Cui Guo, Ze-Hua Zhou., and Obsahuje seznam literatury