Browsing by Subject "Geometria algebraica"
Now showing items 120 of 63

A Koszul complex over skew polynomial rings
(20190101)
Article
Open AccessWe construct a Koszul complex in the category of left skew polynomial rings associated with a flat endomorphism that provides a finite free resolution of an ideal generated by a Koszul regular sequence 
A note on a question of Dimca and Greuel
(Elsevier, 20190122)
Article
Open AccessIn this note we give a positive answer to a question of Dimca and Greuel about the quotient between the Milnor and Tjurina numbers of an isolated plane curve singularity in the cases of one Puiseux pair and semiquasihomogeneous ... 
ACM bundles on cubic surfaces
(2011)
Article
Open AccessWe prove that, for every r 2, the moduli space Ms X.rI c1; c2/ of rank r stable vector bundles with Chern classes c1 D rH and c2 D 1 2 .3r2 r/ on a nonsingular cubic surface X P3 contains a nonempty smooth open ... 
Algebra and geometry in Pietro Mengoli (16251686)
(2003)
Article
Open AccessOne of the most important steps in the research carried out in the seventeenth century into new ways of calculating quadratures was the proposal of algebraic procedures. Pietro Mengoli (16251686), probably the most ... 
Algebraic description of jacobians isogeneous to certain prym varieties with polarization (1,2)
(20180101)
Article
Open AccessFor a class of nonhyperelliptic genus 3 curves C which are twofold coverings of elliptic curves E, we give an explicit algebraic description of all birationally nonequivalent genus 2 curves whose Jacobians are degree 2 ... 
Álgebra geométrica y geometrías ortogonales
(Real Sociedad Matemática Española, 201610)
Article
Restricted access  publisher's policy 
Blending isogeometric analysis and local maximum entropy meshfree approximants
(201309)
Article
Open AccessWe present a method to blend local maximum entropy (LME) meshfree approximants and isogeometric analysis. The coupling strategy exploits the optimization program behind LME approximation, treats isogeometric and LME basis ... 
Comments on “Extremal Cayley Digraphs of Finite Abelian Groups” [Intercon. Networks 12 (2011), no. 12, 125–135]
(201312)
Article
Open AccessWe comment on the paper “Extremal Cayley digraphs of finite Abelian groups” [Intercon. Networks 12 (2011), no. 12, 125–135]. In particular, we give some counterexamples to the results presented there, and provide a correct ... 
Constancy regions of mixed multiplier ideals in twodimensional local rings with rational singularities
(WILEYVCH Verlag GmbH & Co. KGaA, Weinheim, 2018)
Article
Open AccessThe aim of this paper is to study mixed multiplier ideals associated with a tuple of ideals in a twodimensional local ring with a rational singularity. We are interested in the partition of the real positive orthant given ... 
Constraints on the automorphism group of a curve
(20170101)
Article
Open AccessFor a curve of genus > 1 defined over a finite field, we present a sufficient criterion for the nonexistence of automorphisms of order a power of a rational prime. We show how this criterion can be used to determine the ... 
Cotangent models for integrable systems on $b$symplectic manifolds
(201601)
External research report
Open Access 
Counterexample to a conjecture on the algebraic limit cycles of polynomial vector fields
(2004)
Article
Open AccessIn Geometriae Dedicata 79 (2000), 101{108, Rudolf Winkel conjectured: For a given algebraic curve f = 0 of degree m > 4 there is in general no polynomial vector ¯eld of degree less than 2m ¡ 1 leaving invariant f = 0 ... 
Dmodules, BernsteinSato polynomials and Finvariants of direct summands
(20171201)
Article
Open AccessWe study the structure of D modules over a ring R which is a direct sum mand of a polynomial or a power series ring S with coefficients over a field. We relate properties of D modules over R to D modules over S . We ... 
Determining plane curve singularities from its polars
(20160110)
Article
Open AccessThis paper addresses a very classical topic that goes back at least to Plücker: how to understand a plane curve singularity using its polar curves. Here, we explicitly construct the singular points of a plane curve singularity ... 
Differential operators and the Witten genus for projective spaces and Milnor manifolds
(2003)
Article
Open AccessA $genus$ (in the sense of Hirzebruch [4]) is a multiplicative invariant of cobordism classes of manifolds. Classical examples include the numerical invariants given by the signature and the $\widehat{A}$ and Todd genera. ... 
Effective computation of base points of ideals in twodimensional local rings
(20180104)
Article
Open Access© 2018 Elsevier Ltd. We provide an algorithm that allows to describe the minimal logresolution of an ideal in a smooth complex surface from the minimal logresolution of its generators. In order to make this algorithm ... 
Emmy Noether: una contribución extraordinaria y generosa al establecimiento de la Geometría Algebraica
(20090218)
Audiovisual
Open AccessEn la charla se mostrará la importante contribución de la investigación desarrollada por Emmy Noether sobre la teoría de ideales a los fundamentos de la Geometría Algebraica. Su alumno Van der Waerden tuvo un papel clave ... 
Enumerating simplicial decompositions of surfaces with boundaries
(20120402)
Article
Open AccessIt is wellknown that the triangulations of the disc with n + 2 vertices on its boundary are counted by the nth Catalan number C(n) = 1 n+1 (2n n ) . This paper deals with the generalisation of this problem to any compact ... 
Experimental and numerical study of Advanced Transfer Path Analysis applied to a box prototype
(20190101)
Article
Restricted access  publisher's policyAdvanced Transfer Path Analysis (ATPA) is a technique that allows the characterisation of vibroacoustic systems not only from the point of view of contributions but also topologically by means of the path concept. Some of ... 
Generalized CliffordSeveri inequality and the volume of irregular varieties
(20150215)
Article
Open AccessWe give a sharp lower bound for the selfintersection of a nef line bundle L on an irregular variety X in terms of its continuous global sections and the Albanese dimension of X, which we call the generalized CliffordSeveri ...