**Publication date:** Aug 2017

**Abstract:**

Conformal gravity can elegantly solve the problem of spacetime

singularities present in Einstein’s gravity. For every physical

spacetime, there is an infinite family of conformally equivalent

singularity-free metrics. In the unbroken phase, every non-singular

metric is equivalent and can be used to infer the physical properties of

the spacetime. In the broken phase, a Higgs-like mechanism should select

a certain vacuum, which thus becomes the physical one. However, in the

absence of the complete theoretical framework we do not know how to

select the right vacuum. In this paper, we study the energy conditions

of non-singular black hole spacetimes obtained in conformal gravity

assuming they are solutions of Einstein’s gravity with an effective

energy-momentum tensor. We check whether such conditions can be helpful

to select the vacuum of the broken phase.

**Authors:**

Toshmatov, Bobir; Bambi, Cosimo; Ahmedov, Bobomurat; Abdujabbarov, Ahmadjon; Stuchlík, Zdeněk;