# Twisted Gravitational Waves in the Presence of a Cosmological Constant

## TL;DR

This paper presents exact solutions for twisted gravitational waves in general relativity with a cosmological constant, revealing unique conformally flat solutions related to anti-de Sitter spacetime.

## Contribution

It introduces new exact nonlinear solutions for twisted gravitational waves in the presence of a cosmological constant, including a unique conformally flat class.

## Key findings

- Wave fronts have negative Gaussian curvature.
- Existence of a unique conformally flat class due to negative cosmological constant.
- Solutions include part of anti-de Sitter spacetime.

## Abstract

We find exact nonlinear solutions of general relativity that represent twisted gravitational waves (TGWs) in the presence of a cosmological constant. A TGW is a nonplanar wave propagating along a fixed spatial direction with a null Killing wave vector that has a nonzero twist tensor. The solutions all turn out to have wave fronts with negative Gaussian curvature. Among the classes of solutions presented in this paper, we find a unique class of simple conformally flat TGWs that is due to the presence of a negative cosmological constant and therefore represents part of anti-de Sitter spacetime. The properties of this special solution are studied in detail.