Teses e dissertações: Envíos recientes

Mostrando ítems 21-40 de 279

    • Classificação de centros Hamiltonianos polinomiais biquadrados, e isocronicidade trivial versus formas canônicas para aplicações polinomiais no plano de Jacobiano unitário 

      Appis, Raul Felipe (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 10/10/2022)
      This work, we classify a non- degenerate center at the origin of a planar Hamiltonian system associated to a function of the form $H(x,y)=A(x)+B(x)y^2 + C(x)y^4$, where $A$, $B$ and $C$ are polynomials. After seing a ...

    • Estabilidade, instabilidade e fenômenos de concentração em equações de reação e difusão: uma abordagem geométrica 

      Souza, Carolinne Stefane de (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 07/12/2022)
      In this work, we adress the study of stability of a reaction-difusion equation in two domains: in a family of surfaces of revolution without boundary and in a bounded open interval whose diffusion function vanishes at a ...

    • Hipoelipticidade global analítica e Gevrey de sublaplacianos sob condições Diofantinas 

      Moura, Elis Coimbra de (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 22/09/2022)
      In this dissertation we consider the problem of global Gevrey regularity for a class of partial differential operators in the form of a sum of squares of vector fields and we show that these operators are globally Gevrey ...

    • Camadas de heteroestruturas hexagonais planas modeladas por grafos quânticos 

      Souza, Osmar do Nascimento (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 24/08/2022)
      We started this work by reviewing an application of periodic quantum graph theory to model monolayer hexagonal materials with δ_a and δ_b parameters associated with the different types of atoms located in their vertices. ...

    • Fecho integral de módulos, multiplicidades e poliedros de Newton 

      Araújo, Amanda Santos (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 03/08/2022)
      In this work, we study the integral closure of ideals, Newton polyhedra and Newton non-degenerate ideals. Moreover, we present generalizations of these concepts for modules then, we study the characterization of Newton ...

    • Twisted Borel K-theory and isomorphisms between differential models of K-theory 

      Posada, Alffer Gustavo Hernandez (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 04/07/2022)
      In this thesis we discuss some topics about twisted K-theory calculations and equivalences between a couple of differential extension models. We start with a mathematical review of models for twisted K-theory, differential ...

    • Estabilidade assintótica global para equações diferenciais no plano 

      Peixoto, Magda da Silva (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 25/05/1999)
      Let x! = f(x) be a system of differential equations in the plane where / is C1. This work gives sufficient conditions which guarantee that the basin of attraction of an equilibrium point is the plane. This monograph reports ...

    • Extensões H-cleft distinguidas por H-identidades polinomiais 

      Oliveira Jr., Abel Gomes de (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 27/05/2022)
      Our main object of study is the well-known question asking whether the set of polynomials identities distinguishes PI-algebras up to isomorphism. Let k be an algebraically closed field of characteristic 0 and H a non-semisimple ...

    • Compactly-supported and relative integration in differential cohomology 

      Barbosa, Brenno Gustavo (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 11/04/2022)
      In this work, we have constructed more general versions of differential integration maps in differential cohomology theories. Among the obtained versions we can mention the integration with compact supports, the integration ...

    • Soluções positivas para equações elípticas com operadores fracionários 

      Rodriguez Villena, Diana Yovani (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 18/03/2022)
      In this work, we present results of existence, non-existence and multiplicity of positive solutions to elliptic problems involving the fractional p-Laplacian operator and the fractional Laplacian in the critical case, ...

    • Attractors for processes on time-dependent spaces 

      Santos, Vitória Soares dos (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 12/04/2022)
      The goal of this master’s degree dissertation is to study the asymptotic behavior of non-autonomous hyperbolic partial differential equations with time-dependent coefficients. In order to achieve that, we introduce the ...

    • Não unicidade para uma classe de operadores do tipo parabólico 

      Rosas, Marco Antonio Moya (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 18/01/2022)
      In this thesis we consider the non-uniqueness for a class of parabolic operators. We will prove that for certain real analytic perturbation of the Heat Operator there is a non unique solution for the Initial Value Problem.

    • Classes características de variedades topológicas e generalizadas 

      Barbosa, Alex Melges (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 24/03/2022)
      In this work, we will initially present generalized bundles, a concept developed by Fadell with the objective of generalizing vector bundles, Stiefel-Whitney classes andWu’s formula from the context of smooth manifolds ...

    • Polynomial Weingarten surfaces of tubular type 

      Silva, Fernando Gasparotto da (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 04/04/2022)
      This work seeks to contribute to the classification of Weingarten surfaces. More precisely, it fully classifies three families of surfaces (named tubular, cyclic and canal surfaces) in a tridimensional space form (Euclidean, ...

    • Geometric invariants of groups and property R-infty 

      Sgobbi, Wagner Carvalho (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 05/01/2022)
      In this thesis we study property R_\infty for some classes of finitely generated groups by the use of the BNS invariant \Sigma^1 and some other geometric tools. In the combinatorial chapters of the work (4, 5, 6, 10 and ...

    • Leis de conservação: teoria geral 

      Viana, Matheus Magaiver Barbosa (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 24/03/2022)
      In this thesis we study some aspects of the theory of Partial Differential Equations (PDE's), the theory of the existence and the uniqueness of classical solutions to the Cauchy problem u_t+f'(u)u_x=0, u(0,x)=u_0(x) in the ...

    • Ordinary and twisted K-theory 

      Clemente, Gabriel Longatto (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 28/03/2022)
      The main topic of this thesis consists in Ordinary and Twisted Topological K-Theory. We begin by describing generalized cohomology theories through the Eilenberg-Steenrod Axioms, in order to set Ordinary K-Theory in these ...

    • Um princípio de tangência e aplicações 

      Tarazona, Raúl Armando Gómez (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 17/12/2021)
      We present tools, such as a maximum principle for elliptic functions and properties of a-hyperbolic polynomials, to study a tangency principle between two hypersurfaces with r-mean curvatures of a Riemannian manifold, which ...

    • Laplaciano de Dirichlet em faixas com cantos 

      Silva, Kauane de Araujo (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 24/02/2022)
      Let $\Omega_\theta$ be an unbounded V-shaped set of the plane $\mathbb{R}^2$ , that is, a strip with a corner, and consider $ - \Delta^{D}_{\Omega_\theta}$ the Dirichlet Laplacian in $ \Omega_\theta$. In this work, we will ...

    • Um estudo de valorizações transcendentes e algébricas via polinômios-chaves e pares minimais 

      Souza, Caio Henrique Silva de (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 24/02/2022)
      The main goal of this work is to study transcendental valuations and algebraic valuations. To achieve this, we use some of the main objects in Valuation Theory, such as key polynomials, truncations and minimal pairs. These ...