Universality of curvature invariants in critical vacuum gravitational collapse

TL;DR

This paper presents a numerical study of gravitational wave collapse, revealing universal behaviors and echoes near criticality, similar to scalar field collapse, across various initial data configurations.

Contribution

It demonstrates the universality of curvature invariants and echo phenomena in vacuum gravitational collapse, extending understanding beyond scalar fields.

Findings

Universal echoes observed in near-critical spacetimes

Behavior similar to scalar field collapse

Evidence of universality in curvature invariants

Abstract

We report on a numerical study of gravitational waves undergoing gravitational collapse due to their self-interaction. We consider several families of asymptotically flat initial data which, similar to the well known Choptuik's discovery, can be fine-tuned between dispersal into empty space and collapse into a black hole. We find that near-critical spacetimes exhibit behavior similar to the collapse of scalar field: For different families of initial data, we observe universal "echoes" in the form of irregularly repeating approximate scaled copies of the same piece of spacetime.