@Article{Maso-Ferrando_etal2023,
author="Maso-Ferrando, A.
and Sanchis-Gual, N.
and Font, J. A.
and Olmo, G. J.",
title="Birth of baby universes from gravitational collapse in a modified-gravity scenario",
journal="Journal of Cosmology and Astroparticle Physics",
year="2023",
publisher="IOP Publishing Ltd",
volume="06",
number="6",
pages="028--19pp",
optkeywords="modified gravity; Wormholes",
abstract="We consider equilibrium models of spherical boson stars in Palatini f (R) = R + CR2 gravity and study their collapse when perturbed. The Einstein-Klein-Gordon system is solved using a recently established correspondence in an Einstein frame representation. We find that, in that frame, the endpoint is a nonrotating black hole surrounded by a quasi -stationary cloud of scalar field. However, the dynamics in the f (R) frame is dramatically different. The innermost region of the collapsing object exhibits the formation of a finite -size, exponentially-expanding baby universe connected with the outer (parent) universe via a minimal area surface (a throat or umbilical cord). Our simulations indicate that this surface is at all times hidden inside a horizon, causally disconnecting the baby universe from observers above the horizon. The implications of our findings in other areas of gravitational physics are also discussed.",
optnote="WOS:001025474200010",
optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5577), last updated on Sun, 30 Jul 2023 16:21:33 +0000",
issn="1475-7516",
doi="10.1088/1475-7516/2023/06/028",
opturl="https://arxiv.org/abs/2304.12018",
opturl="https://doi.org/10.1088/1475-7516/2023/06/028",
language="English"
}