Superfluid stars and Q-balls in curved spacetime

TL;DR

This paper develops a relativistic model of self-interacting complex scalar fields with logarithmic nonlinearity, demonstrating the existence of stable, finite-mass, asymptotically-flat solutions that could represent superfluid stars, neutron star cores, or Q-balls.

Contribution

It introduces a new relativistic model with logarithmic nonlinearity for scalar fields, showing gravitational equilibria that can model various astrophysical objects and solitons.

Findings

Existence of nonsingular, finite-mass solutions in the model

Solutions can describe superfluid stars and Q-balls

Estimated masses and sizes of these objects

Abstract

Within the framework of the theory of strongly-interacting quantum Bose liquids, we consider a general relativistic model of self-interacting complex scalar fields with logarithmic nonlinearity taken from dense superfluid models. We demonstrate the existence of gravitational equilibria in this model, described by spherically symmetric nonsingular finite-mass asymptotically-flat solutions. These equilibrium configurations can describe both massive astronomical objects, such as bosonized superfluid stars or cores of neutron stars, and finite-size particles and non-topological solitons, such as Q-balls. We give an estimate for masses and sizes of such objects.