Scalar lumps with a horizon

TL;DR

This paper explores new spherically symmetric solutions in scalar field theories coupled to gravity, revealing novel horizon-surrounded scalar lumps that depend on a scalar potential with a barrier consistent with swampland conjectures.

Contribution

It introduces new classes of solutions with scalar lumps and horizons in strong gravity regimes, extending previous static and oscillating solutions.

Findings

Existence of solutions with scalar lumps surrounded by horizons

Solutions where the spatial sphere shrinks inside or outside the horizon

Dependence on scalar potential with a barrier satisfying swampland conjectures

Abstract

We study a self-interacting scalar field theory coupled to gravity and are interested in spherically symmetric solutions with a regular origin surrounded by a horizon. For a scalar potential containing a barrier, and using the most general spherically symmetric ansatz, we show that in addition to the known static, oscillating solutions discussed earlier in the literature there exist new classes of solutions which appear in the strong field case. For these solutions the spatial sphere shrinks either beyond the horizon, implying a collapsing universe outside of the cosmological horizon, or it shrinks already inside of the horizon, implying the existence of a black hole surrounding the scalar lump in all directions. Crucial for the existence of all such solutions is the presence of a scalar field potential with a barrier that satisfies the swampland conjectures.