# Plausible scenario for a generic violation of the weak cosmic censorship conjecture in asymptotically flat four dimensions

## TL;DR

This paper proposes a plausible counterexample to the weak cosmic censorship conjecture in four-dimensional Einstein-Scalar theory, using analysis of the Klein-Gordon equation on Kerr black holes and demonstrating potential nonlinear instability.

## Contribution

It introduces a new scenario where the weak cosmic censorship conjecture may be violated, supported by numerical and analytical analysis of quasinormal modes and backreaction effects.

## Key findings

- Numerical and analytical quasinormal mode spectra agree.
- Evidence of nonlinear instability at late times.
- Potential violation of weak cosmic censorship in this setting.

## Abstract

We present a plausible counterexample to the weak cosmic censorship conjecture in the four-dimensional Einstein-Scalar theory with asymptotically flat boundary conditions. Our setup stems from the analysis of the massive Klein-Gordon equation on a fixed Kerr black hole background. In particular, we construct the quasinormal spectrum numerically, and analytically in the WKB approximation, then go on to compute its backreaction on the Kerr geometry. In the regime of parameters where the analytic and numerical techniques overlap we find perfect agreement. We give strong evidence for the existence of a nonlinear instability at late times.