Gravitational field around a screwed superconducting cosmic string in scalar-tensor theories

Abstract

We obtain the solution that corresponds to a screwed superconducting cosmic string (SSCS) in the framework of a general scalar-tensor theory including torsion. We investigate the metric of the SSCS in Brans-Dicke theory with torsion and analyze the case without torsion. We show that in the case with torsion the space-time background presents other properties different from that in which torsion is absent. When the spin vanish, this torsion is a φ-gradient and then it propagates outside of the string. We investigate the effect of torsion on the gravitational force and on the geodesics of a test-particle moving around the SSCS. The accretion of matter by wakes formation when a SSCS moves with speed v is investigated. We compare our results with those obtained for cosmic strings in the framework of scalar-tensor theory.

Topological mass term in effective Brane-World scenario with torsion

“…Torsion can be related to coupling to fermionic fields [5], alternatively it can be associated with a scalar field gradient for bosons in scalar tensor theories [6,7] or to a rank 2 antisymmetric Kalb-Ramond tensor field as in [3,8].…”

“…Torsion corresponds to the anti-symmetric part of the Affine connection and shows up when one generalizes Einsteins theory of gravity in such a way that the geometry is not only characterized by the curvature [4]. Torsion can be related to coupling to fermionic fields [5], alternatively it can be associated with a scalar field gradient for bosons in scalar tensor theories [6,7] or to a rank 2 antisymmetric Kalb-Ramond tensor field as in [3], [8].…”

Breakdown of the mechanism of forming wakes by a current-carrying string

“…They have shown that the presence of a gravitational scalar field -which from now on we will call generically as "dilaton" -induces a very similar structure as in the case of a wiggly cosmic string [4]. Further, Bezerra and Ferreira [6] showed that, if a torsion is presented, this effect is amplified.…”

Static cosmic strings in space–time with torsion, and strings with electromagnetism

“…Various interior solutions have been investigated by Krisch [23]. Spinning strings that may contain torsion have been studied by Anandan [24], and the effect of screwed superconducing cosmic strings in scalar-tensor theories have also been investigated [25]. In this case the torsion was assumed to arise from a scalar field.…”