Singularities in Low Energy $d=4$ Heterotic String and Brans-Dicke Theories

Abstract

We present the static, spherically symmetric solutions of the low energy $d=4$ string. They form a simple generalisation of the Schwarzschild solution and describe the gravitational field of a spherical star in perturbative string theory. If the Robertson parameter $\gamma$ is different from one, these solutions describe singular objects with naked singularities at their horizons, and whose Hawking temperature is infinite. These objects might represent ``massive remnants'', the end states of black holes. Our analysis also implies that Brans-Dicke theory has a naked singularity. Invoking cosmic censorship conjecture will rule out Brans-Dicke theory.

Comments: 11 pages, preprint TCD-6-93; a mistake is corrected