# Gravitational waves and extra dimensions: a short review

## TL;DR

This review discusses how gravitational waves can be used to test and constrain theories involving extra dimensions, offering new observational avenues to explore the structure of the universe beyond four dimensions.

## Contribution

It provides a concise overview of recent developments in gravitational wave research within extra-dimensional theories, highlighting how gravitational wave observations can constrain extra-dimensional parameters.

## Key findings

- Gravitational wave propagation can limit the size of extra dimensions.
- Amplitude decay of gravitational waves indicates the number of extra dimensions.
- Gravitational waves offer a new method to test extra-dimensional models.

## Abstract

We give a brief review on the recent development of gravitational waves in extra-dimensional theories of gravity. Studying extra-dimensional theories with gravitational waves provides a new way to constrain extra dimensions. After a flash look at the history of gravitational waves and a brief introduction to several major extra-dimensional theories, we focus on the sources and spectra of gravitational waves in extra-dimensional theories. It is shown that one can impose limits on the size of extra dimensions and the curvature of the universe by researching the propagations of gravitational waves and the corresponding electromagnetic waves. Since gravitational waves can propagate throughout the bulk, how the amplitude of gravitational waves decreases determines the number of extra dimensions for some models. In addition, we also briefly present some other characteristics of gravitational waves in extra-dimensional theories.