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We study the implications of a scalar-tensorial gravity for the metric of an isolated self-gravitating superconducting cosmic string. These modifications are induced by an arbitrary coupling of a massless scalar field to the usual tensorial…

General Relativity and Quantum Cosmology · Physics 2016-11-03 C. N. Ferreira , M. E. X. Guimaraes , J. A. Helayel-Neto

The gravitational properties of a local cosmic string in the framework of scalar-tensor gravity are examined. We find the metric in the weak-field approximation and we show that, contrary to the General Relativity case, the cosmic string in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. E. X. Guimarães

We consider a local cosmic string described by the Abelian-Higgs model in the framework of scalar-tensor gravities. We find the metric of the cosmic string in the weak-field approximation. The propagation of particles and light is analysed…

General Relativity and Quantum Cosmology · Physics 2016-08-15 Maria Emília X. Guimarães

We consider static and cylindrically symmetric interior string type solutions in the scalar-tensor representation of the hybrid metric-Palatini modified theory of gravity. As a first step in our study, we obtain the gravitational field…

General Relativity and Quantum Cosmology · Physics 2020-06-25 Tiberiu Harko , Francisco S. N. Lobo , Hilberto M. R. da Silva

We consider the possible existence of gravitationally bound stringlike objects in the framework of the generalized hybrid metric-Palatini gravity theory, in which the gravitational action is represented by an arbitrary function of the Ricci…

General Relativity and Quantum Cosmology · Physics 2021-12-21 Hilberto M. R. da Silva , Tiberiu Harko , Francisco S. N. Lobo , João Luís Rosa

We consider Kasner-type static, cylindrically symmetric interior string solutions in the $f\left(R,L_m\right)$ theory of modified gravity. The physical properties of the string are described by an anisotropic energy-momentum tensor…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Tiberiu Harko , Matthew J. Lake

In this work we made use of a general static cillindrically symmetric metric to find $U(1)$ local cosmic string solutions in the context of the hybrid metric-Palatini theory of gravity in it's scalar-tensor representation. After finding the…

General Relativity and Quantum Cosmology · Physics 2021-12-10 Tiberiu Harko , Francisco S. N. Lobo , Hilberto Silva

The gravitational field of both local and global non static cosmic strings in the context of Lyra geometry are investigated. Local strings are characterized by having an energy momentum tensor whose only non null components are $T_{tt} =…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Farook Rahaman

We study the effect of the geometry and topology of a scalar-tensor cosmic string space-time on the electric and magnetic fields of line sources. It is shown that the dilatonic coupling of the gravity induces effects along the string…

High Energy Physics - Theory · Physics 2009-11-10 I. V. L. Costa , F. A. Oliveira , M. E. X. Guimaraes , F. Moraes

We investigate some consequences of a specific non-conservation of the energy-momentum tensor on the physics of certain cosmic string configurations. This non-conservation is induced by a new gravitational theory recently introduced as an…

General Relativity and Quantum Cosmology · Physics 2019-02-26 E. A. F. Bragança , Thiago R. P. Caramês , Júlio C. Fabris , Antônio de Pádua Santos

We study spatial variations of the fine-structure constant in the presence of static straight cosmic strings in the weak-field approximation in Einstein gravity. We work in the context of a generic Bekenstein-type model and consider a gauge…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. Menezes , P. P. Avelino , C. Santos

We investigate the spacetime of a spinning cosmic string in conformal invariant gravity, where the interior consists of a gauged scalar field. We find exact solutions of the exterior of a stationary spinning cosmic string, where we write…

General Relativity and Quantum Cosmology · Physics 2020-04-15 Reinoud Jan Slagter

In this work we derive an exact solution for the exterior metric of a local cosmic string in an effective theory of gravity, the so-called NDL theory, which is inspired in the Born-Infeld theory. The solution is given by a family of…

General Relativity and Quantum Cosmology · Physics 2012-09-28 W. J. da Rocha , A. L. Naves de Oliveira , M. E. X. Guimaraes

A field-theoretical model for non-singular global cosmic strings is presented. The model is a non-linear sigma model with a potential term for a self-gravitating complex scalar field. Non-singular stationary solutions with angular momentum…

High Energy Physics - Theory · Physics 2010-11-19 Y. Verbin , A. L. Larsen

The modified Gauss-Bonnet gravity can be motivated by a number of physical reasons, including: the uniqueness of a gravitational Lagrangian in four and higher dimensions and the leading order $\alpha^\prime$ corrections in superstring…

High Energy Physics - Theory · Physics 2017-08-23 Ishwaree P. Neupane

In this work we will explore $U(1)$ local cosmic string solutions in the context of the generalized hybrid metric-Palatini theory of gravity in its scalar-tensor representation. Using a general static cylindrically symmetric metric to find…

General Relativity and Quantum Cosmology · Physics 2021-12-13 Hilberto M. R. da Silva , Tiberiu Harko , Francisco S. N. Lobo , João Luís Rosa

We study the cosmological constraints on the variation of the Newton's constant and on post-Newtonian parameters for simple models of scalar-tensor theory of gravity beyond the extended Jordan-Brans-Dicke theory. We restrict ourselves to an…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-07 M. Rossi , M. Ballardini , M. Braglia , F. Finelli , D. Paoletti , A. A. Starobinsky , C. Umiltà

We show that stable local cosmic strings are a generic prediction of supersymmetric models where supersymmetry is broken at scales within a few orders of magnitude of the weak scale and is fed down to the observable sector by gauge…

High Energy Physics - Phenomenology · Physics 2009-10-30 Antonio Riotto

The behaviour of a relativistic scalar particle subject to a scalar potential under the effects of the violation of the Lorentz symmetry in the cosmic string spacetime is discussed. It is considered two possible scenarios of the Lorentz…

High Energy Physics - Theory · Physics 2016-03-16 H. Belich , K. Bakke

Exact solutions of the Einstein field equations with cosmic string and space varying cosmological constant, viz., $\Lambda= \Lambda(r)$, in the energy-momentum tensors are presented. Three cases have been studied: where variable…

Astrophysics · Physics 2009-07-22 Saibal Ray , Farook Rahaman , Utpal Mukhopadhyay
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