Universitat de Barcelona
Now showing items 21-40 of 64
Disorder is present in many systems in nature and in many different versions. For instance, the dislocations of a crystal lattice, or the randomness of the interaction between magnetic moments. One of the most studied ...
This Ph.D. Thesis has been devoted to the preparation and characterisation of bulk Gd5(SixGe1-x)4 alloys and to the study of the magnetocaloric effect at the first-order magnetostructural transition appearing in these ...
En aquest treball de tesi doctoral es presenta l’estudi del magnetisme de diferents materials de naturalesa metal•lorgànica emmarcats en diferents famílies. Per un cantó, tenim molècules d’alt espí amb anisotropia magnètica ...
La pregunta que ha inspirado que ha venido a dar en este trabajo ha sido: ¿Qué papel tuvo la hipótesis adiabática de Paul Ehrenfest en el desarrollo de la teoría cuántica? Para ello se ha tratado de precisar el significado ...
In this thesis we push forward techniques to learn about the large scale structure formation of the universe. The approach is from theory, observations and simulations. From theory we study the growth of four non standard ...
The basic aim of the thesis is the study of the propagation of particles and quasiparticles in non-trivial backgrounds from the quantum field theory point of view. By "non-trivial background" we mean either a non-vacuum ...
L'objectiu del projecte era el d'estudiar diversos aspectes dels forats negres en dimensions més altes que quatre. Concretament, volíem estudiar els anells negres en cinc dimensions amb l'objectiu de generalitzar les ...
LISA Pathfinder (LPF) is an ESA mission, with NASA contributions, devoted to pave the way to the future spaceborne gravitational wave observatory LISA.<br/>The LISA Technology Package (LTP) experiment in the LPF mission ...
In a time when large amounts of data about social, economical, technological, and biological systems are produced in a daily bases, complex networks have become a powerful tool to represent the structure of complex systems. ...
[spa] El propósito de la Tesis es estudiar las posibles modificaciones de la relatividad general a distancias largas. La motivación de dicho estudio se debe tanto a motivos teóricos (la rigidez de la relatividad general ...
[spa] El objetivo de la presente tesis es el estudio de las subestructuras que aparecen a un nivel de resolución mesoscópico en las redes complejas. Dichas subestructuras, que en el campo de las redes complejas son denominadas ...
Complex systems are abundant in our natural environment. In linear systems, the equations of their dynamics can be very difficult to solve, but if they cannot be described with a single characteristic scale, at least they ...
Els treballs presentats en aquesta tesi fan referència a sistemes amb estructures d’escales nanomètriques. L’estructura d'aquests sistemes s’obté mitjançant la formació de monocapes de Langmuir, dipositant dissolucions de ...
[eng] Molecular biophysics is a scientific discipline that studies biomolecules. This discipline has experienced a revolution thanks to the development of single- molecule techniques. These techniques allows us to obtain ...
Viruses are submicroscopic biological entities that need to infect a host cell in order to replicate. In their simplest form viruses are constituted by an infective genetic material and a protein shell (the capsid) that ...
In this thesis we study the Einstein-Aether (E-A) theory from the point of view of its cosmological perturbations. We are interested in the constraints that may be obtained from this analysis and the special features that ...
The goal of this thesis is to study the large scale structure of the Universe from a theoretical point of view. In particular, the different chapters of this thesis focus on developing statistic tools to improve the ...
The work presented in this thesis consists of two distinct parts. The first years of my work focused on the development and improvement of a new equipment built to study magnetic and electrical properties, particularly ...
During the last decades, it has become clear that systems formed by many interacting parts show emergent dynamical properties which are inherently related to the topology of the underlying pattern of connections among the ...
However successful classical general relativity is, it faces non-normalizability problems at the quantum mechanical level. Nevertheless, it predicts the existence of black holes, which are thermal objects that are expected ...
