Spaces Of Constant Curvature
Mostrando 1-11 de 11 artigos, teses e dissertações.
-
1. Hidrodinâmica relativística: a representação de diversos fluidos em relatividade geral
Resumo O tensor de momento-energia é a entidade matemática que representa de forma unificada as fontes de momento e energia no formalismo covariante, tanto em espaços planos, como em espaços curvos. Em espaços curvos o tensor de momento-energia fica conectado a curvatura do espaço-tempo via equação de campo de Einstein. O tensor de momento-energia ca
Rev. Bras. Ensino Fís.. Publicado em: 04/11/2019
-
2. Alguns resultados tipo-Bernstein em variedades semi-riemannianas / Some Bernstein-type results in semi-riemannian manifolds
Nesta tese, estudamos hipersuperfÃcies de tipo-espaÃo completas imersas em variedades semi-Riemannianas, satisfazendo alguma condiÃÃo sobre suas curvaturas de ordem superior, a fim de obtermos resultados tipo-Bernstein. As ferramentas analÃticas que utilizamos sÃo algumas versÃes do princÃpio do mÃximo. No caso em que o ambiente à um espaÃo-tempo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/05/2011
-
3. Sobre a geometria de imersÃes isomÃtricas em variedades de Lorentz conformemente estacionÃrias / On the geometry of varieties of isometric immersions in Lorents stationary conformally
In this thesis we study several aspects of the geometry of conformally stationary Lorentz manifolds and, more particularly, of generalized Robertson-Walker spaces, under the presence of a closed conformal vector field. We initiate by focusing our study on the r-stability and on the strong r-stability of closed spacelike hypersurfaces of conformally stationar
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/12/2010
-
4. CYCLIC MINIMAL SURFACES IN R3, S2 X R AND H2 X R / SUPERFÍCIES MÍNIMAS CÍCLICAS EM R3, S2 X R E H2 X R
In this work we describe minimal surfaces embedded in product spaces M x R, where M = R2, S2 and H2 which are foliated by geodesics (ruled surfaces) and curves of M with constant curvature (cyclic surfaces). In R2 x R, i.e. R3, we shall prove that there exist only two minimal cyclic surfaces which are the catenoid and the Riemann example. Then we characteriz
Publicado em: 2007
-
5. Spherical codes with cyclic symmetries / Codigos esfericos com simetrias ciclicas
Euclidean spherical codes with symmetries are orbits of finite orthogonal matrix groups. These codes are also known as group codes. ln this work, the commutative group codes in even dimensions are viewed on flat tori, which are submanifolds of the sphere. Also, if the matrix group is cyclic, the generated code lies on a knot which wraps around a torus. If th
Publicado em: 2006
-
6. Coordenadas Fricke e empacotamentos hiperbolicos de discos
This work searches elements to determine the packing density of spheres defined by lattices in the hyperbolic plane. We consider the teichmüller space Tg of all closed compacts oriented surfaces of genus 9 ~ 2, which has the hyperbolic plane as universal covering rienmannian surface. It is known that the system of Fricke coordinates in Tg associates each su
Publicado em: 2005
-
7. Alguns aspectos da geometria riemanniana das variedades de Hilbert
The aim of this work is to formalize the local theory of infinite dimensional Riemannian manifold and to study the geometry/ topology when the sectional curvature is bounded by two positive constant. We compare this situation with the finite dimensional case and emphasize the difference. The local theory was already developed since 1960, so we describe, brie
Publicado em: 2002
-
8. Examples of constant mean curvature immersions of the 3-sphere into euclidean 4-space
Mean curvature is one of the simplest and most basic of local differential geometric invariants. Therefore, closed hypersurfaces of constant mean curvature in euclidean spaces of high dimension are basic objects of fundamental importance in global differential geometry. Before the examples of this paper, the only known example was the obvious one of the roun
-
9. Metric rigidity theorems on Hermitian locally symmetric spaces
Let X = Ω/Γ be a compact quotient of an irreducible bounded symmetric domain Ω of rank ≥2 by a discrete group ω of automorphisms without fixed points. It is well known that the Kähler-Einstein metric g on X carries seminegative curvature (in the sense of Griffiths). I show that any Hermitian metric h on X carrying seminegative curvature must be a cons
-
10. On the spectral geometry of spaces with cone-like singularities
I describe an extension of a portion of the theory of the Laplace operator on compact riemannian manifolds to certain spaces with singularities. Although this approach can be extended to include quite general spaces, this paper will confine itself to the case of manifolds with cone-like singularities. These singularities are geometrically the simplest possib
-
11. Holomorphic Embedding of Complex Curves in Spaces of Constant Holomorphic Curvature
A special case of Wirtinger's theorem asserts that a complex curve (two-dimensional) holomorphically embedded in a Kaehler manifold is a minimal surface. The converse is not necessarily true. Guided by considerations from the theory of moduli of Riemann surfaces, we discover (among other results) sufficient topological and differential-geometric conditions f