# Explicit spacetime symmetry breaking in matter: the reversed Vavilov-\v{C}erenkov radiation

## TL;DR

This paper demonstrates that reversed Vavilov-erenkov radiation can occur in magnetoelectric materials when a charge moves near an interface, showing backward radiation in addition to the forward emission.

## Contribution

It introduces the concept of reversed Vavilov-erenkov radiation in magnetoelectric media, expanding understanding of spacetime symmetry breaking effects.

## Key findings

- Reversed Vavilov-erenkov radiation occurs in magnetoelectric interfaces.
- Backward radiation is observed alongside forward emission.
- Angular distribution of radiation is calculated using Green's function.

## Abstract

We show that reversed Vavilov-\v{C}erenkov radiation occurs simultaneously with the forward output in naturally existing materials when an electric charge moves with a constant velocity perpendicular to the planar interface between two magnetoelectric media. Using the Green's function in the far-field approximation we calculate the angular distribution of the radiated energy per unit frequency obtaining a non-zero contribution in the backward direction.