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Rotating black holes in dilatonic Einstein-Gauss-Bonnet theory
Burkhard Kleihaus1, Jutta Kunz, Eugen Radu
1Institut für Physik, Universität Oldenburg, D-26111 Oldenburg, Germany.
Physical Review Letters
|May 17, 2011
Summary
We introduce new Einstein-Gauss-Bonnet-dilaton (EGBD) black holes with higher-curvature corrections. These black holes exhibit unique properties, including angular momentum exceeding the Kerr bound, with potential astrophysical implications.
Area of Science:
- Theoretical physics
- General relativity
- Black hole physics
Background:
- Kerr black holes are fundamental solutions in general relativity.
- Higher-curvature gravity theories offer potential modifications to black hole properties.
- The dilaton field plays a role in string theory and modified gravity.
Purpose of the Study:
- To construct and analyze black hole solutions with higher-curvature corrections.
- To investigate the properties and domain of existence of Einstein-Gauss-Bonnet-dilaton (EGBD) black holes.
- To compare EGBD black holes with Kerr black holes, particularly regarding angular momentum and innermost stable circular orbits.
Main Methods:
- Constructing black hole solutions by incorporating Gauss-Bonnet density coupled to a dilaton.
- Analyzing the mathematical structure and parameter space of the EGBD black hole solutions.
- Comparing key physical characteristics, such as angular momentum and innermost stable circular orbits, with Kerr black holes.
Main Results:
- The domain of existence for EGBD black holes is established, bounded by Kerr, critical, and singular extremal solutions.
- EGBD black holes can possess angular momentum exceeding the classical Kerr bound.
- A generalized Smarr relation is derived for EGBD black holes.
- Differences in innermost stable circular orbits between EGBD and Kerr black holes are identified.
Conclusions:
- EGBD black holes represent a valid generalization of Kerr black holes with distinct properties.
- The potential to exceed the Kerr angular momentum bound has significant theoretical implications.
- Observed differences in innermost stable circular orbits could offer avenues for astrophysical detection and testing of modified gravity theories.
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