Le Matematiche (Dipartimento di Matematica e Informatica, Università degli Studi di Catania)
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Expressing the generalized Fibonacci polynomials in terms of a tridiagonal determinant
Full text linkIn the note, the authors express the generalized Fibonacci polynomials in terms of a tridiagonal determinant. Consequently, they also express the Fibonacci numbers and polynomials in terms of tridiagonal determinants
Some structure theorems on locally convex cones of linear operators
Full text linkIn this paper we investigate the structure of C(P,Q) (the cone of all continuous linear operators from locally convex cone (P,U) into locally convex cone (Q,W), when (P,U) or (Q,W) are inductive or projective limit locally convex cones. We consider some special convex quasiuniform structures on C(P,Q), and prove some structure theorems
OPEN DIFFERENTIABLE MAPPINGS
Full text linkIt is a well-known result that a -mapping defined on an open subset of a Banach space with values in a Banach space whose differential is everywhere onto is an open mapping from onto an open subset of . We prove that this result still holds if is finite-dimensional and both the critical set and the set of critical values have small topological dimensions. The restriction on the set of critical values can be removed if and have same dimension
On dominant rational maps from a very general complete intersection surface in P^4
Full text linkLet S be a very general complete intersection surface of multidegree (d_1,d_2) in P^4. The following problem arises: determine the couples (d_1,d_2) such that the surface S does not have any "non-evident" rational map to other surfaces. By non-evident rational map, we mean non-birational dominant map whose target space is not rational. We give a partial solution, presenting a class of multidegrees (d_1,d_2) which satisfy the above condition
A universal inequality for Riesz potentials on domains on n-spheres
Full text linkIn this short note we give a universal inequality between the largest eigenvalueof the Riesz potentials and non-zero Neumann eigenvalue for domains on hemispheres of S^
Divisors of
No full textWe construct two divisors in the moduli space and we check their invariance and non-invariance under the canonical involution introduced by C. Birkenhake and H. Lange
Bounding the Čebyšev functional for a differentiable function whose derivative is h or λ-convex in absolute value and aplications
Full text linkSome bounds for the Čebyšev functional of a differentiable function whose derivative is h or λ-convex in absolute value and applications for functions of selfadjoint operators in Hilbert spaces via the spectral representation theorem are given
Remarks on the maximum principle for the \infty-Laplacian
No full textIn this note we give three counter-examples which show that the Maximum Principle generally fails for classical solutions of a system and a single equation related to the \infty-Laplacian. The first is the tangential part of the \infty-Laplace system and the second is the scalar \infty-Laplace equation perturbed by a linear gradient term. The interpretations of the Maximum Principle for the system are that of the Convex Hull Property and also of the Maximum Principle of the modulus of the solution
Existence and multiplicity solutions for a -Kirchhoff type systems
Full text linkThis paper is concerned with the existence and multiplicity solutions for a class of (p(x),q(x))-Kirchhoff type systems with Neumann boundary condition. Our technical approach is based on variational methods
Coefficient Bounds for a General Subclass of Bi-Univalent Functions
Full text linkIn the present investigation, we introduce and investigate a new subclass of the function class ∑ of bi-univalent functions defined in the open unit disc. We find estimates on the coefficients |a2| and |a3| for functions in the function class S∑(n, h,λ ). The results presented in this paper improve or generalize the recent works of Jothibasu [13] and other authors