Le Matematiche  

Alexander M. Blokhin

On the example of the Navier-Stokes model, this paper discusses the approach in which the surface of a strong discontinuity in a a compressible viscous gas is considered as a shock wave. It is proved that this approach contains essential lacks. This concl... see more

M. A. Abdou, Khamis J. Mohamed, A. S. Ismal

The Toeplitz matrix and the product Nystrom methods are applied to an integral equation of the second kind. We consider two cases: logarithmic kernel and Hilbert kernel. The two methods are applied to two integral equations with known exact solutions. The... see more

Manuel A. Aguirre Tellez, A. Kananthai

In this paper, we introduce a distributional family K_{a,ß} which is related to the Diamond operator ?^k iterated k-times. At first we study the properties of K_{a,ß} and then we give a sense to the convolution product of K_{a,ß}* K_{a',ß'} .

Manju Purohit, C. L. Parihar, Madhu Tiwari

In this paper, the set {N^{?1 ?2} } of fractional calculus is discussed. It is shown that the set is an Abelian product group for f(z1 , z2 ) = f ? F={ f ; 0 \ne |f_{ ?1?2} | < 8, ?1, ?2 ? R} with continuous indexes ?1 , ?2 , [1]. A new P-transformatio... see more

Vittorino Pata, Alfonso Villani

Given an arbitrary real function f , the set D_f of all points where f admits approximate limit is the maximal (with respect to the relation of inclusion except for a nullset) measurable subset of the real line having the properties that the restriction o... see more

Enrico Carlini

The problem of simultaneous decomposition of binary forms as sums of powers of linear forms is studied. For generic forms the minimal number of linear forms needed is found and the space parametrizing all the possible decompositions is described. More gen... see more

Elena Chierici

The second dual variety of a Segre-Hirzebruch surface linearly normally embedded in a projective space as a 2-regular rational conic bundle is studied by relating it to the classical dual variety of another linearly normal embedding of the underlying surf... see more

Giuseppe Melfi

A positive integer m is a practical number if every positive integer n < m is a sum of distinct divisors of m. Let P_2 (x) be the counting function of the pairs (m, m + 2) of twin practical numbers. Margenstern gave a conjecture on P_2 (x). We prove a ... see more

N. R. Mukherjee

Some stability questions of the Jensen's functional inequality in the setting of 2-normed spaces are derived in this article. Few more results are given on approximate isometries.

Jorge Cordovez

In this paper we determine all Fano varieties which are complete intersections of hypersurfaces in a Grassmannian. Then, in the case Fano's conjecture is satisfied, we give a formula in order to compute the dimension of the Hilbert scheme that parametrise... see more

Francesco Marino

We will prove L^{p,?} regularity results for the gradient of the solution to Dirichlet problem for some equations equations with coefficients in particular spaces.

Filippo Cammaroto, Antonia Chinnì

In this paper, we characterize those bounded from below solutions of a homogeneous wave equation on R^2 which are constant.