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Ultrarelativistic black hole formation
William E East1, Frans Pretorius
1Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Physical Review Letters
|March 26, 2013
Summary
Head-on collisions of fluid particles show black hole formation occurs at lower energies than predicted. Two apparent horizons form and merge near this threshold, driven by gravitational focusing.
Area of Science:
- Astrophysics
- General Relativity
- Numerical Relativity
Background:
- Understanding black hole formation is crucial in astrophysics.
- The hoop conjecture provides a theoretical lower bound for black hole formation.
- Fluid particle collisions are a key area for studying extreme gravity.
Purpose of the Study:
- To investigate black hole formation in head-on fluid particle collisions.
- To compare numerical results with the hoop conjecture.
- To analyze the dynamics of apparent horizons and gravitational radiation.
Main Methods:
- Numerical solution of Einstein-hydrodynamic equations.
- Simulation of fluid particle collisions in the kinetic energy dominated regime (γ = 8 to 12).
Main Results:
- Black hole formation threshold is a few times lower than hoop conjecture estimates.
- Two distinct apparent horizons form and merge near the threshold.
- Gravitational radiation reaches luminosities of 0.014 c(5)/G, carrying 16 ± 2% of total energy.
Conclusions:
- Gravitational focusing explains the observed horizon dynamics.
- Numerical simulations provide insights into black hole formation mechanisms.
- The study refines our understanding of gravitational wave emission from extreme events.
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