Critical collapse in the spherically-symmetric Einstein-Vlasov model

TL;DR

This paper investigates critical phenomena in the spherically symmetric Einstein-Vlasov system with massless particles, revealing type I behavior, non-universal critical solutions, and insights into angular momentum's role.

Contribution

It provides the first detailed numerical analysis of critical collapse in the Einstein-Vlasov system with massless particles, highlighting non-universality and scaling properties.

Findings

Evidence for type I critical behavior at black hole threshold.

Different initial data lead to distinct critical solutions.

Indications of weak universality in lifetime scaling exponent.

Abstract

We solve the coupled Einstein-Vlasov system in spherical symmetry using direct numerical integration of the Vlasov equation in phase space. Focusing on the case of massless particles we study critical phenomena in the model, finding strong evidence for generic type I behaviour at the black hole threshold that parallels what has previously been observed in the massive sector. For differing families of initial data we find distinct critical solutions, so there is no universality of the critical configuration itself. However we find indications of at least a weak universality in the lifetime scaling exponent, which is yet to be understood. Additionally, we clarify the role that angular momentum plays in the critical behaviour in the massless case.