Second Order Gauge Theory

A gauge theory of second order in the derivatives of the auxiliary field is constructed following Utiyama's program. A novel field strength $G=\partial F+fAF$ arises besides the one of the first order treatment, $F=\partial A-\partial A+fAA$. The associated conserved current is obtained. It has a new feature: topological terms are determined from local invariance requirements. Podolsky Generalized Eletrodynamics is derived as a particular case in which the Lagrangian of the gauge field is $L_{P}\propto G^{2}$. In this application the photon mass is estimated. The SU(N) infrared regime is analysed by means of Alekseev-Arbuzov-Baikov's Lagrangian.Comment: 27 pages. No figure. Final versio

Hamilton-Jacobi Approach for First Order Actions and Theories with Higher Derivatives

In this work we analyze systems described by Lagrangians with higher order derivatives in the context of the Hamilton-Jacobi formalism for first order actions. Two different approaches are studied here: the first one is analogous to the description of theories with higher derivatives in the hamiltonian formalism according to [Sov. Phys. Journ. 26 (1983) 730; the second treats the case where degenerate coordinate are present, in an analogy to reference [Nucl. Phys. B 630 (2002) 509]. Several examples are analyzed where a comparison between both approaches is made

General Relativity in two dimensions: a Hamilton-Jacobi constraint analysis

We will analyze the constraint structure of the Einstein-Hilbert first-order action in two dimensions using the Hamilton-Jacobi approach. We will be able to find a set of involutive, as well as a set of non-involutive constraints. Using generalized brackets we will show how to assure integrability of the theory, to eliminate the set of non-involutive constraints, and to build the field equations

Weak-field approximation of effective gravitational theory with local Galilean invariance

We examine the weak-field approximation of locally Galilean invariant gravitational theories with general covariance in a $(4+1)$-dimensional Galilean framework. The additional degrees of freedom allow us to obtain Poisson, diffusion, and Schr\"odinger equations for the fluctuation field. An advantage of this approach over the usual $(3+1)$-dimensional General Relativity is that it allows us to choose an ansatz for the fluctuation field that can accommodate the field equations of the Lagrangian approach to MOdified Newtonian Dynamics (MOND) known as AQUAdratic Lagrangian (AQUAL). We investigate a wave solution for the Schr\"odinger equations.Comment: 15 page

Gauge Formulation for Higher Order Gravity

This work is an application of the second order gauge theory for the Lorentz group, where a description of the gravitational interaction is obtained which includes derivatives of the curvature. We analyze the form of the second field strenght, $G=\partial F +fAF$, in terms of geometrical variables. All possible independent Lagrangians constructed with quadratic contractions of $F$ and quadratic contractions of $G$ are analyzed. The equations of motion for a particular Lagrangian, which is analogous to Podolsky's term of his Generalized Electrodynamics, are calculated. The static isotropic solution in the linear approximation was found, exhibiting the regular Newtonian behaviour at short distances as well as a meso-large distance modification.Comment: Published versio

Cosmic acceleration from second order gauge gravity

We construct a phenomenological theory of gravitation based on a second order gauge formulation for the Lorentz group. The model presents a long-range modification for the gravitational field leading to a cosmological model provided with an accelerated expansion at recent times. We estimate the model parameters using observational data and verify that our estimative for the age of the Universe is of the same magnitude than the one predicted by the standard model. The transition from the decelerated expansion regime to the accelerated one occurs recently (at $\sim9.3\;Gyr$).Comment: RevTex4 15 pages, 1 figure. Accepted for publication in Astrophysics & Space Scienc

Formalismo de Hamilton-Jacobi à la Carathéodory

Aqui traremos a descrição do formalismo de Hamilton-Jacobi para sistemas regulares como desenvolvido no livro de Carathéodory, seguida por dois exemplos que mostram sistematicamente sua aplicabilidade

Formalismo de Hamilton-Jacobi à la Carathéodory

Aqui traremos a descrição do formalismo de Hamilton-Jacobi para sistemas regulares como desenvolvido no livro de Carathéodory, seguida por dois exemplos que mostram sistematicamente sua aplicabilidade.We will bring the description of the Hamilton-Jacobi formalism for regular systems as developed in Carathéodory's book, followed by two examples that show its applicability.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Neutron Stars on Modified Teleparallel Gravity

International audienceWe investigate compact objects in modified teleparallel gravity with realistic equations of state. We propose a modification on Teleparallel Equivalent of General Relativity, then an appropriate tetrad is applied on the field equations. A specific set of relations showing a equivalency between our gravitational model and the New General Relativity is found. The conservation equation implies that our Tolman-Oppenheimer-Volkoff equations are presented with an effective pressure and energy density, where a free parameter {̱e̱ṯa̱}̱3 is used to construct them. Numerical analysis using realistic equations of state is made, the behavior of mass, radius and the relation mass-radius as functions of {̱e̱ṯa̱}̱3 is also investigated