Universitat de Barcelona
Now showing items 21-40 of 50
Dados un ideal I de un anillo Noetheriano R y un sistema multiplicativo S de R, se establecen tres tipos de caracterizaciones para la equivalencia; la equivalencia lineal, y la igualdad entre las filtraciones I-adica, ...
Estudiem el grup fonamental de varietat algebràïques complexes i la seva monodromia. Les línies d'estudi són:<br/><br/>- L'àlgebra de Malcev dels grups fonamentals de varietats compactes Kahler: Provem que no pot ser lliure, ...
Entenderemos por anillos "blowup" cierto tipo de anillos graduados asociados a filtraciones de un anillo conmutativo A. Los anillos blowup aparecen a menudo en Algebra Conmutativa y Geometría Algebraica. Expondremos a ...
This thesis seeks to contribute to a deeper understanding of the moduli spaces <i>M-sub X, H (r; c1,., Cmin{r;n}</i>) of rank <i>r</I>, <i>H</i>-stable vector bundles E on an <i>n</i>-dimensional variety <i>X</I>, with ...
In this tesis we study numerical propieties of surfaces and threefolds, mainly fibred over curves, the so called "slope" of the fibration. We prove partially a conjecture of Fujita on the semiampleness of the direct image ...
The aim of this work is to study the ring-theoretic properties of the diagonals of a Rees algebra, which from a geometric point of view are the homogenous coordinate rings of embeddings of blow-ups of projective varieties ...
La teoría algebraica de números tiene sus inicios en los trabajos de Kummer sobre la ecuación de Fermat. En los anillos ciclotómicos deja de ser cierto el teorema fundamental de la aritmética: los elementos descomponen en ...
L'estudi dels grups fuchsians i les funcions automorfes associades s'inicià en el segle XIX en els treballs de H. Poincaré, R. Fricke i F. Klein, principalment. A partir dels anys seixanta, al llarg de nombrosos treballs, ...
Sigui R l'anell de polinomis amb coeficients en un cos k de característica zero. El nostre objectiu és, tot seguint la linia de recerca encetada per G. Lyubeznik, utilitzar en profunditat la teoria de D-mòduls per tal ...
En aquesta tesi estudiem versions refinades del problema invers de la teoria de Galois sobre el cos Q dels racionals, que s'obtenen quan prefixem determinades condicions de ramificació. Ens plantejem, per exemple, les ...
En esta tesis se estudia el problema de clasificación de estructuras simplécticas definidas en un entorno de una órbita singular compacta de un sistema completamente integrable sobre una variedad simpléctica para las cuales ...
EN CASTELLANO:<br/><br/>La localización es una técnica bien conocida en álgebra conmutativa y geometría algebraica. Muchas de las propiedades formales de las localizaciones de módulos son compartidas por otras transformaciones ...
The original interest in sandwiched singularities comes from a natural question posed by J. Nash in the early sixties to H. Hironaka: “Does a finite succession of Nash transformations or normalized Nash transformations ...
The results of this thesis contribute to the program of developing a higher arithmetic intersection theory. These results constitute chapters 3 and 5. Chapters 2 and 4 consist of the preliminary results needed for chapters ...
A first goal of this thesis is to contribute to the knowledge of cohomological properties of non-standard multigraded modules. In particular we study the Hilbert function of a non-standard multigraded module, the asymptotic ...
The background of this dissertation is the inverse Galois problem.<br/>Which finite groups can occur as Galois groups of an extension of the rational field? This problem was first considered by D. Hilbert, and it still ...
To determine whether a syzygy bundle on PN is stable, or semistable, is a long-standing problem in algebraic geometry. It is closely related to the problem of finding the Hilbert function and the minimal free resolution ...
This thesis is about Galois theory.<br/><br/>The development of a Galois theory for differential equations analogous to the classical Galois theory for polynomial equations was already an aim of S. Lie in the 19th century. ...
This thesis contains new results about the representability of cohomological functors defined on a subcategory of compact objects (with respect to a fixed cardinal) of a well generated triangulated category. Classical ...
The subject of this thesis lies at the junction of mainly three topics: construction of large families of Arithmetically Cohen-Macaulay indecomposable vector bundles on a given projective variety X, the shape (i.e, the ...
