Echoes from bounded universes

TL;DR

This paper introduces a new class of modified Ellis wormholes with a bounded core, analyzing their geometry and scalar perturbations to understand their potential observational signatures.

Contribution

It constructs and analyzes a novel class of wormholes with a bounded core, exploring their geometric properties and scalar perturbation behavior.

Findings

Geodesic completeness is maintained despite the core shrinking to zero.

Scalar perturbations exhibit distinctive quasinormal mode profiles.

The geometry influences the time-domain signals of perturbations.

Abstract

We construct a general class of modified Ellis wormholes, where one asymptotic Minkowski region is replaced by a bounded 2-sphere core, characterized by asymptotic finite areal radius. We pursue an in-depth analysis of the resulting geometry, outlining that geodesic completeness is guaranteed also when the radial function asymptotically shrinks to zero. Then, we study the evolution of scalar perturbations, bringing out how these geometric configurations can in principle affect the time-domain profiles of quasinormal modes, pointing out the distinctive features with respect to other black holes or wormholes geometries.