High Energy Collisions of Black Holes Numerically Revisited

TL;DR

This paper employs advanced numerical relativity methods to accurately estimate the maximum gravitational radiation from high-energy black hole collisions, refining previous results and reducing spurious initial data effects.

Contribution

It introduces improved initial data techniques enabling simulations at near-light speeds, leading to a more precise estimate of maximum gravitational wave emission.

Findings

Maximum radiated energy estimated at 13% of total mass.

New initial data reduces spurious radiation significantly.

Results align with thermodynamic estimates and previous numerical studies.

Abstract

We use fully nonlinear numerical relativity techniques to study high energy head-on collision of nonspinning, equal-mass black holes to estimate the maximum gravitational radiation emitted by these systems. Our simulations include improvements in the construction of initial data, subsequent full numerical evolutions, and the computation of waveforms at infinity. The new initial data significantly reduces the spurious radiation content, allowing for initial speeds much closer to the speed of light, i.e. $v\sim0.99c$. Using these new techniques, We estimate the maximum radiated energy from head-on collisions to be $E_{\text{max}}/M_{\text{ADM}}=0.13\pm0.01$. This value differs from the second-order perturbative $(0.164)$ and zero-frequency-limit $(0.17)$ analytic computations, but is close to those obtained by thermodynamic arguments $(0.134)$ and by previous numerical estimates $(0.14\pm0.03)$.