Elliptic Geometry
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. 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
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2. Teoria de regularidade para equaÃÃes elÃpticas totalmente nÃo lineares com potenciais singulares e problemas de fronteira livre assintÃticos / Fully nonlinear singularly perturbed elliptic equations and limiting free boundary problems
In this work we develop a fully nonlinear theory for singularly perturbed elliptic equations problems with high energy activation. We esta-blish uniform and optimal gradient estimates of solutions and prove that minimal solutions are non-degenerated. For problems governed by concave equations, we establish uniform weak geometric properties of approximating l
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/11/2010
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3. Uma possível inserção das geometrias não-euclidianas no ensino médio
Este trabalho pretende discutir a possibilidade de introduzir as Geometrias Não-Euclidianas no currículo escolar do Ensino Médio. Para isto, procuramos lembrar a forma e estrutura lógica que Euclides tentou dar à Geometria e em seguida apresentamos um texto introdutório sobre duas daquelas Geometrias: Geometria Hiperbólica e Elíptica, orbitando em to
Publicado em: 2010
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4. Heisenberg spin textures on a cylinder with topological defects
The present work aims to study equilibrium configurations of spins on a cylinder with topological defects such as screw dislocation and deficit angle. By making use of elliptic-f expansion method, which in turn utilizes the Jacobi elliptic functions, we obtain exact solutions of the nonlinear sigma model in this geometry. We have significant changes in the q
Brazilian Journal of Physics. Publicado em: 2009-12
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5. Elliptic flow, eccentricity and eccentricity fluctuations
Differential studies of elliptic flow are one of the most powerful tools in studying the initial conditions and dynamical evolution of heavy ion collisions. The comparison of data from Cu+Cu and Au+Au collisions taken with the PHOBOS experiment at RHIC provides new information on the interplay between initial geometry and initial particle density in determin
Braz. J. Phys.. Publicado em: 2007-06
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6. Potencials and electric fields inside and outside resistive conductors carrying steady currents / Potenciais e campos eletricos dentro e fora de condutores resistivos com correntes constantes
In Chapter 1 we present an introduction about the electric field inside and outside resistive conductors carrying steady currents. We also discuss the distribution of surface charges that maintains the current fiow and its relation with these electric fields. We present some experiments related with these electric fields outside conductors with steady curren
Publicado em: 2005
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7. An experimental investigation of the effects of nozzle ellipticity on the flow structure of co-flow jet diffusion flames
The flow structure of cold and ignited jets issuing into a co-flowing air stream was experimentally studied using a laser Doppler velocimeter. Methane was employed as the jet fluid discharging from circular and elliptic nozzles with aspect ratios varying from 1.29 to 1.60. The diameter of the circular nozzle was 4.6 mm and the elliptic nozzles had approximat
Journal of the Brazilian Society of Mechanical Sciences. Publicado em: 2001
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8. SOLUÇÕES NUMÉRICAS PARA PLOBLEMAS DE OTIMIZAÇÃO DE FORMAS GEOMÉTRICAS ASSOCIADAS À EQUAÇÕES DIFERENCIAIS PARCIAIS ELÍTPTICAS / NUMERICAL SOLUTIONS FOR SHAPE OPTIMIZATION PROBLEMS ASSOCIATED WITH ELLIPTIC PARTIAL DIFFERENTIAL EQUATIONS
This work is directed at the problem of determining numerical solutions for shape optimization problems associated with elliptic partial differential equations. Our primarily motivation is the problem of determining optimal shapes in order to minimize the heat lost of a body, given a fixed volume of insulation and a fixed internal (or external) geometry. The
Publicado em: 1991
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9. Some nonlinear elliptic equations from geometry
We describe some recent work on certain nonlinear elliptic equations from geometry. These include the problem of prescribing scalar curvature on 𝕊n, the Yamabe problem on manifolds with boundary, and the best Sobolev inequality on Riemannian manifolds.
National Academy of Sciences.
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10. Twist fields, the elliptic genus, and hidden symmetry
We combine infinite dimensional analysis (in particular a priori estimates and twist positivity) with classical geometric structures, supersymmetry, and noncommutative geometry. We establish the existence of a family of examples of two-dimensional, twist quantum fields. We evaluate the elliptic genus in these examples. We demonstrate a hidden SL(2,ℤ) symme
The National Academy of Sciences.
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11. Geometry and analysis of Shimizu L-functions
The values of 0 of Shimizu L-functions are realized as the signature defects of framed manifolds. This settles a conjecture of Hirzebruch [Hirzebruch, F. (1973) Enseign. Math. 19, 183-281] affirmatively. The proof employs the spectral theory of elliptic operators.
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12. Padé approximations and diophantine geometry
Using methods of Padé approximations we prove a converse to Eisenstein's theorem on the boundedness of denominators of coefficients in the expansion of an algebraic function, for classes of functions, parametrized by meromorphic functions. This result is applied to the Tate conjecture on the effective description of isogenies for elliptic curves.