Macroscopic superstrings as interpolating solitons

TL;DR

This paper demonstrates that certain supergravity solutions interpolate between known spacetimes and new supersymmetric compactifications, revealing macroscopic superstring configurations as interpolating solitons with potential extensions to M-theory.

Contribution

It introduces a novel supersymmetric $S^7$ compactification in supergravity, connecting superstring solutions to membrane solutions in eleven dimensions.

Findings

Superstring solutions interpolate between Minkowski space and $S^7$ compactification.

The divergence of the dilaton can be removed by reinterpreting the solution as an M-theory membrane.

Analytic extension through horizons reveals interior regions with singularities.

Abstract

It is known that, in string sigma-model metric, the `extreme' fivebrane solution of D=10 supergravity interpolates between D=10 Minkowski spacetime and a supersymmetric $S^3$ compactification to a linear dilaton vacuum. We show here that, in {\it fivebrane} sigma-model metric, the extreme string solution of D=10 supergravity interpolates between Minkowski spacetime and a hitherto unknown supersymmetric $S^7$ compactification of d=10 supergravity to a three-dimensional anti-de Sitter generalization of the linear dilaton vacuum, which may be invariantly characterized in terms of conformal Killing vectors. The dilaton field diverges near the string core but this divergence may be eliminated by re-interpreting the string solution as the extreme membrane solution of 11-dimensional supergravity. We show that the latter has an analytic extension through a regular degenerate event horizon to an interior region containing a curvature singularity. We obtain analogous results for other extended object solutions of supergravity theories.