A census for curves and surfaces with diophantine stability over finite fields 

    Vrioni, Brikena (Date of defense: 2021-10-29)

    An algebraic variety defined over a field is said to have Diophantine stability for an extension of this field if the variety does not acquire new points in the extension. Diophantine stability has a growing interest due ...

    Algebraic and semi-algebraic phylogenetic reconstruction 

    Garrote López, Marina (Date of defense: 2021-07-22)

    Phylogenetics is the study of the evolutionary history and relationships among groups of biological entities (called taxa). The modeling of those evolutionary processes is done by phylogenetic trees whose nodes represent ...

    Arithmetic applications of the Euler systems of Beilinson-Flach elements and diagonal cycles 

    Rivero Salgado, Óscar (Date of defense: 2021-02-12)

    The main objective of this dissertation is the exploration of certain arithmetic applications of the Euler systems of Beilinson--Flach elements and diagonal cycles. Euler systems have been proved to be a very powerful tool ...

    Aspectos geométricos del control disipativo de sistemas mecànicos y sistemas no holónomos 

    Yániz Fernández, Francisco Javier (Date of defense: 2002-11-29)

    El tratamiento intrínseco de cuestiones relacionadas con la Teoría de Control no lineal a través de la aplicación de técnicas propias de la geometría diferencial ha sido en los últimos años un tema de interés para muy ...

    Bernstein-Sato polynomial of plane curves and Yano's conjecture 

    Blanco Fernández, Guillem (Date of defense: 2020-04-16)

    The main aim of this thesis is the study of the Bernstein-Sato polynomial of plane curve singularities. In this context, we prove a conjecture posed by Yano about the generic b-exponents of a plane irreducible curve. In ...

    bm-Symplectic manifolds: symmetries, classification and stability 

    Planas Bahí, Arnau (Date of defense: 2020-09-30)

    This thesis explores classification and perturbation problems for group actions on a class of Poisson manifolds called $b^m$-Poisson manifolds. $b^m$-Poisson manifolds are manifolds which are symplectic away from a ...

    Contribució a l'estudi geomètric de subespais invariants respecte a transformacions i sistemes lineals 

    Compta Creus, Albert (Date of defense: 2001-10-19)

    Mitjançant tècniques geomètriques, abordem les qüestions següents:<br/><br/>(i) Estudi (caracterització, classificació, famílies diferenciables,...) d'una classe destacada de subespais invariants, els anomenats ...

    Generalized Delaunay triangulations : graph-theoretic properties and algorithms 

    Cano Vila, María del Pilar (Date of defense: 2020-06-25)

    This thesis studies different generalizations of Delaunay triangulations, both from a combinatorial and algorithmic point of view. The Delaunay triangulation of a point set S, denoted DT(S), has vertex set S. An edge uv ...

    Geometrical aspects of contact mechanical systems and field theories 

    Rivas Guijarro, Xavier (Date of defense: 2021-12-17)

    Many important theories in modern physics can be stated using the tools of differential geometry. It is well known that symplectic geometry is the natural framework to deal with autonomous Hamiltonian mechanics. This admits ...

    Global Hamiltonian dynamics on singular symplectic manifolds 

    Oms, Cédric (Date of defense: 2020-10-02)

    In this thesis, we study the Reeb and Hamiltonian dynamics on singular symplectic and contact manifolds. Those structures are motivated by singularities coming from classical mechanics and fluid dynamics. We start by ...

    Integrable systems on b-symplectic manifolds 

    Kiesenhofer, Anna (Date of defense: 2016-12-21)

    The study of b-symplectic manifolds was initiated in 2012 by the works of Victor Guillemin, Eva Miranda and Ana Rita Pires (Adv. Math. 264 (2014), 864¿896). These manifolds, which can be understood as symplectic manifolds ...

    Metric-aware optimization of high-order meshes for curved adaptivity 

    Aparicio Estrems, Guillermo (Date of defense: 2023-04-26)

    (English) To enhance the simulation accuracy when the solution presents sharp curved features, the community of high-order methods has started to curve not only the boundary but also the interior of unstructured high-order ...

    Modelització de corbes i superfícies amb aplicacions al disseny geomètric assistit per ordinador i a l'arquitectura 

    Monreal, Amadeo (Date of defense: 2001-12-17)

    En primer lloc, s'evidencia que el disseny que involucra grafisme es pot analitzar com articulat en dos nivells o etapes, un de concepció, intel·lectual, i un altre d'execució, manual o físic, ambdós sempre en interrelació ...

    A multisymplectic approach to gravitational theories 

    Gaset Rifà, Jordi (Date of defense: 2018-07-25)

    The theories of gravity are one of the most important topics in theoretical physics and mathematical physics nowadays. The classical formulation of gravity uses the Hilbert-Einstein Lagrangian, which is a singular ...

    New geometrical and dynamical techniques for problems in celestial mechanics 

    Braddell, Róisín (Date of defense: 2021-02-17)

    In this thesis, we study the application of symplectic geometry, regular and singular, to symplectic dynamical systems.We start with a motivating case: the relation between symplectic foliations and global transverse ...

    Nodal distributions on the high-dimensional simplex for high-order interpolation and integration 

    Jiménez Ramos, Albert (Date of defense: 2023-06-28)

    (English) To simulate unsteady phenomena on complex moving geometry, computational scientists and engineers have been interested in unstructured space-time discretizations. These space-time discretizations aim to overcome ...

    On some spectral and combinatorial properties of distance-regular graphs and their generalizations 

    Diego, Víctor (Date of defense: 2017-11-24)

    In this work we present the study we did in Graph Theory. In the firsts chapteres of the tesis we study the pieces of information that can be obtained from a graph: the spectrum of the adjacency matrix, the preintersection ...

    The geometry and topology of steady Euler flows, integrability and singular geometric structures 

    Cardona Aguilar, Robert (Date of defense: 2021-05-26)

    In this thesis, we make a deep investigation of the geometry and dynamics of several objects (singular or not) appearing in nature. The main goal is to study rigidity versus flexibility dynamical behavior of the objects ...