Cosmic string in scalar - tensor gravities

Abstract

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 scalar-tensor gravitation exerces a force on non-relativistic, neutral test particle. This force is propor-*

Gravitational field around a timelike current-carrying screwed cosmic string in scalar-tensor theories

“…The potential V (ϕ, σ) triggering the spontaneous symmetry breaking can be written in the most general case as 19) where λ ϕ , λ σ , f ϕσ and m σ are coupling constants. Considering the analogy with the ordinary cosmic string case, this potential possesses all the ingredients necessary to drive the formation of a screwed cosmic string with a time-like current.…”

Local cosmic string in generalized scalar tensor theory

“…It deserves mention that in a recent work by Guimarães [8], the solutions of Einstein's equations for a gauge string have been presented in a weak field approximation of the field equations in similar ω-varying scalar tensor theory. Guimarães' work does not consider the phenomenological expression for T µ ν , i.e.…”

Dynamics of a self-gravitating thin string in scalar - tensor theories of gravitation

“…We remark that g ab = δ ab + O(ρ 2 ). According to metric (17), the metric of the world sheet is 18) and the extrinsic and mean curvature of the world sheet are K aAB = 1 2 ∂ a g AB | ρ=0 and K a = K aAB γ AB (19) since X(0) = 1 and X ′ (0) = 0. Further calculations, that we do not reproduce here, show that the scalar field φ of such a solution is very particular.…”