Cerenkov radiation and scalar stars

TL;DR

This paper investigates whether scalar stars can produce Cerenkov radiation from charged particles, concluding that stable boson stars cannot, but certain soliton stars might under specific conditions, affecting their detectability.

Contribution

It demonstrates that stable boson stars do not emit Cerenkov radiation, while soliton stars may under specific parameters, refining the understanding of observational signatures of scalar stars.

Findings

Stable boson stars do not produce Cerenkov radiation.

Soliton stars could emit Cerenkov radiation for certain boson masses.

Detection prospects via Cerenkov radiation are limited but not entirely ruled out.

Abstract

We explore the possibility that a charged particle moving in the gravitational field generated by a scalar star could radiate energy via a recently proposed gravitational \v{C}erenkov mechanism. We numerically prove that this is not possible for stable boson stars. We also show that soliton stars could have \v{C}erenkov radiation for particular values of the boson mass, although diluteness of the star grows and actual observational possibility decreases for the more usually discussed boson masses. These conclusions diminish, although do not completely rule out, the observational possibility of actually detecting scalar stars using this mechanism, and lead us to consider other forms, like gravitational lensing.