Le Matematiche (Dipartimento di Matematica e Informatica, Università degli Studi di Catania)
Not a member yet
1189 research outputs found
Sort by
Fano manifolds as ample divisors
Get PDFWe study polarized manifolds (X, L) with L having a smooth element A in its linear system which is a Fano manifold of coindex 3 and second Betti number greater or equal than 2
Symmetrization results for a multi-exponent, degenerate and anisotropic electrostatic problem
Get PDFIn this paper, we give some isoperimetric inequalities for the capacity c p of an anisotropic configuration
A BGK type approximation for the collision operator of the transport equation for semiconductors
Get PDFIn the attempt of obtaining macroscopic models which describe the flow of electrons through a semiconductor crystal, many authors start from the Boltzmann transport equation, often using a generalized BGK type approximation for the collision operator. In this work, by means of this approximation, we shall show that it is possible to obtain a new drift-diffusion equation valid in the high electric field regime
Approximation properties of certain modified Szasz-Mirakyan operators
Get PDFWe introduce certain modified Szasz - Mirakyan operators in exponential weighted spaces of functions of one variable. We give theorems on the degree of approximation and the Voronovskaya type theorem
The global ring of a smooth projective surface
Get PDFLet X be a smooth projective variety over an algebraically closed field k. We associate to X , in a functorial way, a multigraded k-algebra G(X), called the global ring of X . We find some results when dim X = 2, and we explicitly determine the global ring in two particular cases
Holomorphic self-maps of singular projective curves
Get PDFHere we classify all complex singular irreducibile projective curves. X , such that there exists a holomorphic map f : X → X with f locally biholomorphic at each point of X_{reg} and with deg( f ) ≥ 2 : X is rational and either it has a unique singular point with two branches or it has exactly two singular points, both unibranch
On some local properties of fuzzy manifold and its folding
Get PDFThis paper is a continuation of [5]. It introduces the local properties of the fuzzy manifold. the fuzzy vector field in a fuzzy tangent space will be defined. Theorems governing the relation between the folding of the fuzzy tangent space and the folding of the fuzzy manifold are deduced
Clifford line manifolds
Get PDFThis article presents a new distribution of Clifford Klein manifolds. Special kinds of the distribution, under some assumption, are studies. The geometrical properties of the K-manifolds in the considered distribution are given. The relations between Gauss, mean, scalar normal and Lipschitz-Killing curvatures are obtained. The methods adapted here as in [1], [2] and [5]
Holomorphic vector bundles on holomorphically convex surface
No full textHere we study holomorphic vector bundles on a two-dimensional holomorphically convex complex manifold Y . We present some characterizations of Y under which torsion free sheaves are filtrable. In the case when Y = X × C, where X is a connected compact Riemann surface, we study in what sense every holomorphic vector bundle may be approximated by a sequence of algebraic vector bundles
On Hadamard algebras
Get PDFTopological algebras of sequences of complex numbers are introduced, endowed with a Hadamard product type. The complex homomorphisms on these algebras are characterized, and units, prime cyclic ideals, prime closed ideals, and prime minimal ideals, discussed. Existence of closed and maximal ideals are investigated, and it is shown that the Jacobson and nilradicals are both trivial