# Electromagnetic wormholes via handlebody constructions

## TL;DR

This paper introduces electromagnetic wormholes created through handlebody constructions that alter space topology, enabling invisible tunnels for electromagnetic waves while keeping the tunnel entrances detectable.

## Contribution

It presents a novel method to engineer electromagnetic wormholes using handlebody topological modifications, expanding cloaking device concepts to include topological tunneling.

## Key findings

- Electromagnetic waves can pass through invisible tunnels.
- The topology of space can be effectively changed for wave propagation.
- The constructed devices act as electromagnetic wormholes.

## Abstract

Cloaking devices are prescriptions of electrostatic, optical or electromagnetic parameter fields (conductivity $\sigma(x)$, index of refraction $n(x)$, or electric permittivity $\epsilon(x)$ and magnetic permeability $\mu(x)$) which are piecewise smooth on $\mathbb R^3$ and singular on a hypersurface $\Sigma$, and such that objects in the region enclosed by $\Sigma$ are not detectable to external observation by waves. Here, we give related constructions of invisible tunnels, which allow electromagnetic waves to pass between possibly distant points, but with only the ends of the tunnels visible to electromagnetic imaging. Effectively, these change the topology of space with respect to solutions of Maxwell's equations, corresponding to attaching a handlebody to $\mathbb R^3$. The resulting devices thus function as electromagnetic wormholes.