Trapped surfaces and horizons in static massless scalar field spacetimes

TL;DR

This paper investigates the existence and structure of trapped surfaces and horizons in static, spherically symmetric spacetimes with massless scalar fields, showing that no event horizons form regardless of asymptotic flatness.

Contribution

It generalizes previous results by proving the absence of event horizons in all such static scalar field spacetimes, not just asymptotically flat cases.

Findings

No event horizon exists in these spacetimes.

The results hold regardless of asymptotic flatness.

Additional properties of these models are discussed.

Abstract

We consider here the existence and structure of trapped surfaces, horizons and singularities in spherically symmetric static massless scalar field spacetimes. Earlier studies have shown that there exists no event horizon in such spacetimes if the scalar field is asymptotically flat. We extend this result here to show that this is true in general for spherically symmetric static massless scalar field spacetimes, whether the scalar field is asymptotically flat or not. Other general properties and certain important features of these models are also discussed.