On horizons and wormholes in k-essence theories

  title={On horizons and wormholes in k-essence theories},
  author={Kirill A. Bronnikov and J{\'u}lio C{\'e}sar Fabris and Denis Campos Rodrigues},
  journal={Gravitation and Cosmology},
We study the properties of possible static, spherically symmetric configurations in k-essence theories with the Lagrangian functions of the form F(X), X ≡ ϕ,αϕ,α. A no-go theorem has been proved, claiming that a possible black-hole-like Killing horizon of finite radius cannot exist if the function F(X) is required to have a finite derivative dF/dX. Two exact solutions are obtained for special cases of kessence: one for F(X) = F0X1/3, another for F(X) = F0|X|1/2 − 2Λ, where F0 and Λ are… 

Instability of some k-essence spacetimes

We study the stability properties of static, spherically symmetric configurations in k-essence theories with the Lagrangians of the form $F(X)$, $X \equiv \phi_{,\alpha} \phi^{,\alpha}$. The

Kinetic gravity braiding wormhole geometries

This work presents the full gravitational field equations in a static and spherically symmetric traversable wormhole background, and outlines the general constraints at the wormhole throat, imposed by the flaring-out conditions.

Static, spherically symmetric solutions with a scalar field in Rastall gravity

Rastall’s theory belongs to the class of non-conservative theories of gravity. In vacuum, the only non-trivial static, spherically symmetric solution is the Schwarzschild one, except for a very

The simplest wormhole in Rastall and k-essence theories

The geometry of the Ellis–Bronnikov wormhole is implemented in the Rastall and k-essence theories of gravity with a self-interacting scalar field. The form of the scalar field potential is determined

Duality between k-essence and Rastall gravity

The k-essence theory with a power-law function of $$(\partial \phi )^2$$(∂ϕ)2 and Rastall’s non-conservative theory of gravity with a scalar field are shown to have the same solutions for the metric

On Black Hole Structures in Scalar-Tensor Theories of Gravity

We review some properties of black hole structures appearing in gravity with a massless scalar field, with both minimal and nonminimal coupling. The main properties of the resulting cold black holes

General constraints on Horndeski wormhole throats

The generic constraints analyzed in this work serve as a consistency check of the main solutions obtained in the literature and draw out new avenues of research in considering applications of specific subclasses of the Horndeski theory to wormhole physics.

Rastall’s theory of gravity: spherically symmetric solutions and the stability problem

We study the stability of static, spherically symmetric solutions of Rastall's theory in the presence of a scalar field with respect to spherically symmetric perturbations. It is shown that the



Scalar Fields in Multidimensional Gravity. No-Hair and Other No-Go Theorems

Global properties of static, spherically symmetric configurations with scalar fields of sigma-model type with arbitrary potentials are studied in D dimensions, including models where the space-time

Cold scalar-tensor black holes: causal structure, geodesics, stability.

We study the structure and stability of spherically symmetric Brans-Dicke black-hole type solutions with an infinite horizon area and zero Hawking temperature, existing for negative values of the

On the stability of scalar-vacuum space-times

We study the stability of static, spherically symmetric solutions to the Einstein equations with a scalar field as the source. We describe a general methodology of studying small radial perturbations

Spherically symmetric false vacuum: No go theorems and global structure

We enumerate all possible types of spacetime causal structures that can appear in static, spherically symmetric configurations of a self-gravitating, real, nonlinear, minimally coupled scalar field

Instability of wormholes supported by a ghost scalar field: I. Linear stability analysis

We examine the linear stability of static, spherically symmetric wormhole solutions of Einstein's field equations coupled to a massless ghost scalar field. These solutions are parametrized by the

Ether flow through a drainhole - a particle model in general relativity

The Schwarzchild manifold of general relativitytheory is unsatisfactory as a particle model because the singularity at the origin makes it geodesically incomplete. A coupling of the geometry of

''No-hair'' theorems for the Abelian Higgs and Goldstone models

We examine the question of whether black holes can have associated external massive vector and/or scalar fields, when the masses are produced by spontaneous symmetry breaking. Working throughout in

Scalar mesostatic field with regard for gravitational effects

(Foreword by translator.) The aim of present translation is to clarify the historically important question who was the pioneer in obtaining of exact static solutions of Einstein equations minimally

Essentials of k essence

We recently introduced the concept of ``k-essence'' as a dynamical solution for explaining naturally why the universe has entered an epoch of accelerated expansion at a late stage of its evolution.