Le Matematiche  

Pietro De Poi

In this paper we study the higher secant varieties of rational normal scrolls, in particular we give them as determinantal varieties. From this we can obtain, in some cases, the sequence of secant defects, generalizing to a class of varieties and to every... see more

Ion Armeanu

In this note we shall study the structure of the finite groups having a nonlinear faithful monomial irreducible character of minimal degree.

Alexander Andreev, Giuseppe Zappalà

This paper deals with a nonautonomous differential equation, precompact in the sense of G.R. Sell and Z. Artstein. We investigate the eventual asymptotic stability and total stability of this equation with infinitesimal perturbations using Liapunov functi... see more

M. Morandi Cecchi, R. Nociforo, P. Patuzzo Grego

A finite-element numerical method to solve a weak formulation of quasi-linear parabolic problems on space-time domain governed by Burgers equation is given. Stability and errors estimates theorems for the numerical solution are proved for smooth initial c... see more

Maria Cristina Floreno, Giovanni Novelli

This paper presents some preliminary results arising within a general framework concerning the development of software tools for fuzzy arithmetic. The program is in a preliminary stage. What has been already implemented consists of a set of routines for e... see more

Aleksandra Sternal, Blazei Szmanda

Asymptotic and oscillatory behaviour of solutions of some class nonlinear difference equations is studied.

Paola Cavaliere, Maria Longobardi, Antonio Vitolo

In this paper we deal with the multiplication operator u ? W^{k,p} (O) ? gu ? L^q (O), with g belonging to a space of Morrey type. We apply our results in order to establish an a-priori bound for the solutions of the Dirichlet problem concerning elliptic ... see more

Harold Exton

A special case of the biconfluent Heun equation which is not reducible to a form of a hypergeometric equation is solved by means of a Laplace transform. The solutions are double series which exhibit a type of orthogonality comparable in some respects to t... see more

Chu Wenchang

We specialise an ingeniously contrived identity to obtain a plethora of startling combinatorial identities. Limiting cases include well known evaluations of ?(2), ?(4) and ?(6).

Salvador Gigena

The method of qualitative analysis is used, as applied to a class of fourth order, nonlinear ordinary differential equations, in order to classify, both locally and globally, two classes of hypersurfaces of decomposable type in affine geometry: those with... see more

Giuseppe Dattoli, Amalia Torre

q analog of bessel functions, symmetric under the interchange of q and q^ -1 are introduced. The definition is based on the generating function realized as product of symmetric q-exponential functions with appropriate arguments. Symmetric q-Bessel functio... see more

Cristina Giannotti

In the theory of second order elliptic equations, in non divergence form, two non linear elliptic operators, which are non convex with respect to the second derivatives, are studied. Such operators are called maximinimal because of their extremal properti... see more

P. Cavaliere, A. D'Ottavio, F. Leonetti, C. Musciano

See directly the article.