Search results for "Geometria"

Bollettino di Matematica Pura e Applicata

2008

Binary Hamming codes and Boolean designs

2021

AbstractIn this paper we consider a finite-dimensional vector space $${\mathcal {P}}$$ P over the Galois field $${\text {GF}}(2),$$ GF ( 2 ) , and the family $${\mathcal {B}}_k$$ B k (respectively, $${\mathcal {B}}_k^*$$ B k ∗ ) of all the k-sets of elements of $$\mathcal {P}$$ P (respectively, of $${\mathcal {P}}^*= {\mathcal {P}} \setminus \{0\}$$ P ∗ = P \ { 0 } ) summing up to zero. We compute the parameters of the 3-design $$({\mathcal {P}},{\mathcal {B}}_k)$$ ( P , B k ) for any (necessarily even) k, and of the 2-design $$({\mathcal {P}}^{*},{\mathcal {B}}_k^{*})$$ ( P ∗ , B k ∗ ) for any k. Also, we find a new proof for the weight distribution of the binary Hamming code. Moreover, we…

Best approximation and variational inequality problems involving a simulation function

2016

We prove the existence of a g-best proximity point for a pair of mappings, by using suitable hypotheses on a metric space. Moreover, we establish some convergence results for a variational inequality problem, by using the variational characterization of metric projections in a real Hilbert space. Our results are applicable to classical problems of optimization theory.

Our Friend and Mathematician Karl Strambach

2020

This paper is dedicated to Karl Strambach on the occasion of his 80th birthday. Here we want to describe our work with Prof. Karl Strambach.

Increasing chains and discrete reflection of cardinality

2013

Combining ideas from two of our previous papers, we refine Arhangel'skii Theorem by proving a cardinal inequality of which this is a special case: any increasing union of strongly discretely Lindelof spaces with countable free sequences and countable pseudocharacter has cardinality at most continuum. We then give a partial positive answer to a problem of Alan Dow on reflection of cardinality by closures of discrete sets.

Tractado subtilissimo d'arithmética y geometria / Co[m]puesto por ... fray Jua[n] de Hortega ; agora de nuevo emendado... por Juan Lagarto, y antes …

1563

Sig. a-z8, A-I8. - Data d'impr.: "Acabose en ocho dias del mes de Abril. Año de M.D.LXIII" Els grav. xil. son figures geomètriques. - Capitals grav. Lletra gòtica. - Reclams al final de cada quadern. - Errates de fol.

In hoc libro contenta Epitome compendiosaq[ue] introductio in libros arithmeticos diui Seuerini Boetij : adiecto familiari commentario dilucidata / […

1503

Autors agafats de les epístoles dedicatories Sign.: a-o8 Praxis numerandi certi quibusdam regulis constricta / [Iudocus Clichtoueus ... ]. Introductio in Geometriam ... Liber de quadratura circuli ; Liber de cubicatione sphere ; Perspectiua introductio / [Carolus Bouillus...]. Insuper Astronomicon / [Iacobi Fabri stapulensis Grav. xil. als marges Minúscules per a inicials

Segunda ynpresion de la primera parte del arte y uso de architectura ... : con el primer libro deuclides [sic] traducido del latin en romançe / Conp…

1667

Sig. a6, A-Ee6, Ff4 Els grav. xil. - Port. grav. Errates de pag.

Quotients of the Dwork Pencil

2012

In this paper we investigate the geometry of the Dwork pencil in any dimension. More specifically, we study the automorphism group G of the generic fiber of the pencil over the complex projective line, and the quotients of it by various subgroups of G. In particular, we compute the Hodge numbers of these quotients via orbifold cohomology.

Groups acting freely on Calabi-Yau threefolds embedded in a product of del Pezzo surfaces

2011

In this paper, we investigate quotients of Calabi-Yau manifolds $Y$ embedded in Fano varieties $X$, which are products of two del Pezzo surfaces — with respect to groups $G$ that act freely on $Y$. In particular, we revisit some known examples and we obtain some new Calabi-Yau varieties with small Hodge numbers. The groups $G$ are subgroups of the automorphism groups of $X$, which is described in terms of the automorphism group of the two del Pezzo surfaces.