Generalized Galileon Model -- cosmological reconstruction and the Vainshtein mechanism --

TL;DR

This paper provides explicit formulas and a reconstruction method for generalized Galileon models, analyzing their stability, the Vainshtein mechanism, and the possibility of scalar hair in static, spherically symmetric spacetimes.

Contribution

It introduces explicit equations and a reconstruction framework for generalized Galileon models, including stability conditions and analysis of the Vainshtein mechanism.

Findings

Reconstruction of actions reproducing arbitrary universe expansion.

Conditions for stable, attractor solutions.

Demonstration of the Vainshtein mechanism reducing Newton law corrections.

Abstract

Explicit formulae of the equations in the generalized Galileon models are given. We also develop the formulation of the reconstruction. By using the formulation, we can explicitly construct an action which reproduces an arbitrary development of the expansion of the universe. The conditions how the reconstructed solution becomes stable and therefore it becomes an attractor solution are also given. Working in the static and spherically symmetric space-time, we investigate how the Vainshtein mechanism works in the generalized Galileon model and the correction to the Newton law becomes small. It is also shown that any spherically symmetric and static geometry can be realized by properly choosing the form of the action, which may tell that the solution could have fourth hair corresponding to the scalar field.