Conformally coupled theories and their deformed compact objects: from black holes, radiating spacetimes to eternal wormholes

TL;DR

This paper explores a higher order conformally coupled scalar-tensor theory, analyzing black holes, radiating spacetimes, and wormholes, revealing new solutions and regularizing naked singularities through disformal transformations.

Contribution

It introduces a novel conformally coupled scalar-tensor theory derived from higher dimensions, and constructs new black hole, wormhole, and radiating solutions with regularized singularities.

Findings

Found asymptotically flat black hole solutions.

Discovered eternal wormholes from naked singularities.

Extended solutions to include slow rotation and radiation.

Abstract

We study a higher order conformally coupled scalar tensor theory endowed with a covariant geometric constraint relating the scalar curvature with the Gauss-Bonnet scalar. It is a particular Horndeski theory including a canonical kinetic term but without shift or parity symmetry for the scalar. The theory also stems from a Kaluza-Klein reduction of a well defined higher dimensional metric theory. Properties of an asymptotically flat spherically symmetric black hole are analyzed, and new slowly rotating and radiating extensions are found. Through disformal transformations of the static configurations, gravitating monopole-like solutions and eternal wormholes are presented. The latter are shown to extract from spacetime possible naked singularities, yielding completely regular and asymptotically flat spacetimes.