Le Matematiche (Dipartimento di Matematica e Informatica, Università degli Studi di Catania)
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0-dimensional subschemes of curves lying on a smooth quadric surface
Get PDFWe characterize all the possible Hilbert functions for 0-dimensional subschemes of an irreducible curve C lying on a smooth quadric surface in the projective 3-space
Groups with the Rédei property
Get PDFLet G be a finite abelian group of type (4, 4, 2) or ( p^2 , p), where p is a prime. Assume that AB is a direct product giving G, where A and B are subsets of G both containing the identity element of G. Then A or B lies in a proper subgroup of G
Hölder classes relative to degenerate elliptic operators as interpolation spaces
No full textThe well known characterization ofHölder classes as interpolation spaces is here extended under suitable hypotheses to a class of spaces wherethe Hölder continuity is given in terms of an intrinsic distance relative to degenerate elliptic operators of Hörmander type
Generalized set-valued variational inequalities
Get PDFIn this paper, we introduce and study a new class of variational inequalities, which is called generalized set-valued variational inequality. The projection technique is used to establish the equivalence among generalized set-valued variational inequalities, fixed point problems and generalized set-valued Wiener-Hopf equations. This equivalence is used to study the existence of a solution of set- valued variational inequalities and to suggest a number of iterative algorithms for solving variational inequalities. We also consider the auxiliary principle technique to study the existence of a solution of the generalized set-valued variational inequalities and to suggest a general and novel iterative algorithm. In addition, we have shown that the auxiliary principle technique can be used to find the equivalent differentiable optimization problem for the generalized set-valued variational inequalities. The results proved in this paper represent a significant refinement and improvement of the previous results
Causal (anticausal) Bessel derivative and the ultrahyperbolic Bessel operator
Get PDFLet B^α_C and B^α_A be ultrahyperbolic Bessel operator causal (anticausal) of the order α defined by B^α_C f = G_α ( P + i0, m, n) ∗ f , B^α f = G_α ( P −i0, m, n) ∗ f and let D^α_C and D^α_A be generalized causal (anticausal) Bessel derivative of order α defined by D^α_C f = G_{−α} ( P − i0, m, n) ∗ f , D^α_A f =G_{−α} ( P + i0, m, n) ∗ f . In this note we give a sense to several relations of type: B^α_C (B^β_ A f ) + B^α_A (B^β_C f ), D^ α_C (D^β_ A f ) + D^α_A (D^β_C f ), . .
M_λ ipergruppoidi matroidali. Applicazioni λ-lineari e automorfismi di M_λ-ipergruppoidi
Get PDFIn this paper we forward in the investigation of the matroidal M_λ -hypergrupoids introduced in [13]. We give necessary and sufficient conditions for such hypergrupoid to be matroidal; moreover, we find its cardinality and we analyse the properties of the corresponding omomorphisms. The paper gives also a characterization of the group Λ(G_λ), that is the one of the automorphisms of the hypergroupoid G λ ; this hypergroupoid is obtained by a given group G, an element of its λ and the action of G on G determined by the same operation of G
Sulle curve di genere massimo
Get PDFLet G(d, s) be the maximum genus of a smooth irreducible curve in P^3 of degree d not contained in any surfaces of degree less then s and G(d,s,σ ) the maximum genus of curves as before subject to the further condition that their general plane section is not contained in a plane curve of degree less then σ . We give a characterization of the couples (d,s) such that G(d, s, σ ) = G(d, s) for σ = s, s − 1
On the lifting problem in codimension two
Get PDF In this note we prove a special case of a conjecture of Mezzetti [5]
Optimal integrability in B^q_p classes
Get PDFEquations for the best integrability exponent, for monotonic functions in one-dimensional Gehring and Muckenhoupt classes, are unified in more general Reverse Holder Inequality classes. Furthermore, the result is extended by removing the monotonicity assumptions
