Le Matematiche (Dipartimento di Matematica e Informatica, Università degli Studi di Catania)
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Cones of divisors of blow-ups of projective spaces
Get PDFWe investigate Mori dream spaces obtained by blowing-up the n-dimensional complex projective space at n + 1, n + 2 or n + 3 points in very general position. Using toric techniques we study the movable cone of the blow-up of Pn at n + 1 points, its decomposition into nef chambers and the action of the Weyl group on the set of chambers. Moreover, using different methods, we explicitly write down the equations of the movablecone also for Pn blown-up at n + 2 points
Pragmatic 2010
Get PDFThe twelfth edition of the PRAGMATIC Summer School took place in Catania between August 30 – September 17, 2010. The lecturers were Prof. Paltin Ionescu (University of Bucharest) and Prof. Jarosław Antoni Wiśniewski (University of Warsaw), assisted by Dr. José Carlos Sierra (ICMAT Madrid) and Dr. Luis Eduardo Solá-Conde (URJC Madrid). The school was attended by eighteen students coming from Italy, Iran, Republic of Korea, Poland, Romania and Spain
Subordination and superordination properties for analytic functions involving Wright’s functions
Get PDFIn the present investigation, we obtain some subordination and superordination results for the Hadamard product of certain normalized analytic functions in the open unit disk involving the linear operator introduced in [J. Dziok and R. K. Raina, Demonstratio Math., 37 (3) (2004), 533–542]. Several consequences of the results are presented. It is also pointed out that one of the main results (Theorem 2.8 below) provides a corrected form of the proof stated in two recent known results
Linear fractional transportation problem with varying demand and supply
Get PDFIn this paper, we investigate the transportation problem with fractional objective function when the demand and supply quantities are varying. A set of mathematical programs is obtained to determine the objective value. Due to varying economic policies in the global world, it is hard to specify the supply and demand quantities for transportation problem. A transportation problem with fractional objective function is based on a network structure consisting of a finite number of nodes and arcs attached to them. After the derivation, we obtained the result in range, where the total transportation cost would appear. In addition to allowing for simultaneous changes in supply and demand values, the total cost bounds are calculated directly. This methodology would be very beneficial in the decision making. A numerical example has given in this paper for the support of theory
Approximating the Stieltjes integral by using the generalized trapezoid rule
Get PDFAccurate approximations for the Stieltjes integral by the generalized trapzoid rule. The generalized trapezoid rule is established on the notion of the derivative of function with respect to an increasing function, defined in [9]
International workshop at Messina
Get PDFThe first International WorkshopVariational, Topological and Set-Valued Methods for Nonlinear Differential Problemswas held during April 14 –16 2010, at the Engineering Faculty of the University of Messina
Regularity of some method of summation for double sequences
Get PDFSome generalization of Toeplitz method of summation is introduced for double sequences and condition of regularity of it is obtained
Analytical solution of space-time fractional Fokker Planck equations by generalized differential transform method
Get PDFIn the present paper, we use generalized differential transform method (GDTM) to derive solutions of some linear and nonlinear space-time fractional Fokker–Planck equations (FPE) in closed form. The space and time fractional derivatives are considered in Caputo sense and the solutions are obtained in terms of Mittag-Leffler functions
On differential subordinations and argument inequalities associated with the generalized hypergeometric functions
Get PDFThe main object of this paper is to derive several interesting argument properties of a linear operator H_{p,q,s}^{m,μ}(α₁) associated with the generalized hypergeometric functions
Cox rings of du Val singularities
Get PDFIn this note we introduce Cox rings of singularities and explicitly compute them in the case of du Val singularities Dn , E6 , E7 and E8