Spinning Black Binaries in de Sitter Space

Area of Science:

• General Relativity
• Black Hole Physics
• Numerical Relativity

Background:

• Black hole binaries are key to understanding gravitational waves.
• The inclusion of a positive cosmological constant (Λ) complicates black hole solutions.
• Stationary, axisymmetric black hole solutions are fundamental in general relativity.

Purpose of the Study:

• To numerically construct stationary, rotating black hole binaries in general relativity with a positive cosmological constant.
• To investigate the properties of these binary systems, specifically their entropy.
• To provide initial data for simulations of black hole binary mergers.

Main Methods:

• Numerical construction of spacetime geometries.
• Application of Einstein's field equations for general relativity with a cosmological constant.
• Analysis of black hole properties, including spin and entropy.

Main Results:

• Successfully constructed stationary, rotating black binaries with a positive cosmological constant.
• Found that these binary systems possess less entropy than a single Kerr-Schwarzschild-de Sitter black hole with equivalent total angular momentum and cosmological horizon entropy.
• Demonstrated continuous nonuniqueness in general relativity solutions without matter.

Conclusions:

• The study establishes new exact solutions for rotating black hole binaries in a universe with a positive cosmological constant.
• The findings on entropy have implications for understanding black hole thermodynamics.
• The generated initial data are vital for future numerical relativity simulations of binary black hole mergers.