Imaging Topological Solitons: the Microstructure Behind the Shadow

TL;DR

This paper investigates topological solitons in string theory that mimic black holes in appearance and scattering but are smooth and horizonless, offering potential alternatives to traditional black holes.

Contribution

It demonstrates that topological solitons can resemble black holes in observational properties while lacking horizons, providing new insights into gravitational solutions in string theory.

Findings

Topological solitons have similar apparent size to black holes.

Photon scattering and redshift effects mimic horizon-like behavior.

These solutions are smooth, horizonless, and consistent with string theory models.

Abstract

We study photon geodesics in topological solitons that have the same asymptotic properties as Schwarzschild black holes. These are coherent states in string theory corresponding to pure deformations of spacetime through the dynamics of compact extra dimensions. We compare these solutions with Schwarzschild black holes by computing null geodesics, deriving Lyapunov exponents, and imaging their geometries as seen by a distant observer. We show that topological solitons are remarkably similar to black holes in apparent size and scattering properties, while being smooth and horizonless. Incoming photons experience very high redshift, inducing phenomenological horizon-like behaviors from the point of view of photon scattering. Thus, they provide a compelling case for real-world gravitational solitons and topological alternatives to black holes from string theory.