Search results for "Singularities"
showing 10 items of 34 documents
La singularité de O’Grady
2006
Let M 2 v M_{2v} be the moduli space of semistable sheaves with Mukai vector 2 v 2v on an abelian or K 3 K3 surface where v v is primitive such that ⟨ v , v ⟩ = 2 \langle v,v \rangle =2 . We show that the blow-up of the reduced singular locus of M 2 v M_{2v} provides a symplectic resolution of singularities. This provides a direct description of O’Grady’s resolutions of M K 3 ( 2 , 0 , 4 ) M_{K3}(2,0,4) and M A b ( 2 , 0 , 2 ) M_{Ab}(2,0,2) . Résumé. Soit M 2 v M_{2v} l’espace de modules des faisceaux semi-stables de vecteur de Mukai 2 v 2v sur une surface K 3 K3 ou abélienne où v v est primitif tel que ⟨ v , v ⟩ = 2 \langle v,v \rangle =2 . Nous montrons que l’éclatement de M 2 v M_{2v} le…
On stability of logarithmic tangent sheaves. Symmetric and generic determinants
2021
We prove stability of logarithmic tangent sheaves of singular hypersurfaces D of the projective space with constraints on the dimension and degree of the singularities of D. As main application, we prove that determinants and symmetric determinants have stable logarithmic tangent sheaves and we describe an open dense piece of the associated moduli space.
Archeologia fluviale
2020
Palermo sta sul mare, ma ha un rapporto difficile con il mare. La questione sorge, nel XVII secolo, al momento della costruzione dei Quattro Canti di Città o piazza Vigliena, quando l’asse di fondazione fenicio (il Cassaro, con giacitura EO) venne intersecato da una strada ortogonale (via Maqueda, con giacitura NS) capace di cancellare - con la formazione di un centro - la relazione che si era istituita, nel tempo, tra monti e mare attraverso la città. Da quel momento in poi l’espansione, all’interno della Conca d’oro, avvenne prevalentemente verso Nord, allontanando la città sempre di più dalla linea di costa a causa, anche, di Monte Pellegrino e di Pizzo Sella, due promontori abbandonati …
Integrable Hamiltonian systems with swallowtails
2010
International audience; We consider two-degree-of-freedom integrable Hamiltonian systems with bifurcation diagrams containing swallowtail structures. The global properties of the action coordinates in such systems together with the parallel transport of the period lattice and corresponding quantum cells in the joint spectrum are described in detail. The relation to the concept of bidromy which was introduced in Sadovski´ı and Zhilinski´ı (2007 Ann. Phys. 322 164–200) is discussed.
Domestic Violence in Separated Couples in Italian Context: Communalities and Singularities of Women and Men Experiences
2018
Relationship breakdown and separation represent a critical aspect in domestic violence. Few studies have investigated domestic violence in separated couples. Moreover, there is a need for a more in depth analysis of gender differences that could enhance the comprehension of the phenomenon. The primary aim of this research was to analyze, through a qualitative approach, which kinds of domestic violence are characteristic or major in separated couples in the Italian context, where this phenomenon has not yet been sufficiently investigated. Participants are 60 separated couples (mean age: M = 48; F = 44) who attended a Family Mediation Center. A descriptive study was conducted using grounded t…
Du verbe instrumental dans la musique subsaharienne
2021
Sub-Saharan music results from the spoken language/instrumental language relation, directed by an oral culture. In this culture, these languages transmit ? beyond their singularities ? messages thanks to either a coded signal known by the linguistic community or previously defined among a group of individuals, or is used as a true meta-language copied on the articulated and usual language used every day. Here, an instrumental musical speech can then imitate and reproduce the tonal inflexions of the language to make its matter understandable. This fact is the natural result of a strong interaction and interrelation between the spoken language and the music as well as the conception that the …
Rescaling principle for isolated essential singularities of quasiregular mappings
2012
We establish a rescaling theorem for isolated essential singularities of quasiregular mappings. As a consequence we show that the class of closed manifolds receiving a quasiregular mapping from a punctured unit ball with an essential singularity at the origin is exactly the class of closed quasiregularly elliptic manifolds, that is, closed manifolds receiving a non-constant quasiregular mapping from a Euclidean space.
Smooth 4-Dimensional Thickening of Singular 2-Dimensional Complex in the non Compact Case.
2009
L'articolo estende la teoria dell'ingrossamento 4-dimensionale nel caso non-proprio.
Rotation Forms and Local Hamiltonian Monodromy
2017
International audience; The monodromy of torus bundles associated with completely integrable systems can be computed using geometric techniques (constructing homology cycles) or analytic arguments (computing discontinuities of abelian integrals). In this article, we give a general approach to the computation of monodromy that resembles the analytical one, reducing the problem to the computation of residues of polar 1-forms. We apply our technique to three celebrated examples of systems with monodromy (the champagne bottle, the spherical pendulum, the hydrogen atom) and to the case of non-degenerate focus-focus singularities, re-obtaining the classical results. An advantage of this approach …
Local monomialization of generalized real analytic functions
2011
Generalized power series extend the notion of formal power series by considering exponents ofeach variable ranging in a well ordered set of positive real numbers. Generalized analytic functionsare defined locally by the sum of convergent generalized power series with real coe cients. Weprove a local monomialization result for these functions: they can be transformed into a monomialvia a locally finite collection of finite sequences of local blowingsup. For a convenient frameworkwhere this result can be established, we introduce the notion of generalized analytic manifoldand the correct definition of blowing-up in this category.