Kerr-Bertotti-Robinson黑洞的能量提取：极区坍缩与负能量质子俘获
Energy extraction from Kerr--Bertotti--Robinson black holes: polar region collapse and the capture of negative energy protons
- Chongqing Normal University（重庆师范大学）
- Chongqing Jiaotong University（重庆交通大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究通过分析Kerr-Bertotti-Robinson黑洞在均匀磁场中的带电粒子运动，发现极区俘获负能量质子可实现能量提取，且无需各向异性密度分布。
AI中文摘要：
Kerr-Bertotti-Robinson黑洞是爱因斯坦-麦克斯韦方程的一个精确解，描述的是渐近均匀磁场中的旋转黑洞。它与Wald解中的Kerr黑洞不同：磁力线不再是圆柱形的，常数\u0027A_φ\u0027线在大距离处趋于饱和，且界面\u0027E·B=0\u0027不再是锥形，而是随半径收缩并最终消失。通过逐点确定带电粒子的加速度，我们发现极区中质子被向外驱动、电子被向内驱动，而在赤道区则相反；极区随磁场增强而收缩。被俘获的质子携带负能量和负角动量，而被俘获的电子携带正能量和正角动量。通过规范不变的通量判据固定俘获域，并在(r,θ)平面上积分，我们发现弱磁场下黑洞获得质量，而强磁场下发生能量提取。能量提取可以在通常的球对称密度下实现，无需引入Wald解中Kerr黑洞所需的各向异性密度分布。
英文摘要：
The Kerr-Bertotti-Robinson black hole is an exact Einstein-Maxwell solution describing a rotating black hole in an asymptotically uniform magnetic field. It differs from the Kerr black hole in the Wald solution: the magnetic field lines are no longer cylindrical, with the constant-\(A_ϕ\) lines saturating at large distances, and the interface \(\vec{E}\cdot\vec{B}=0\) is no longer a cone but contracts with radius and eventually disappears. Determining the acceleration of charged particles pointwise, we find that protons are driven outward and electrons inward in the polar region, and vice versa in the equatorial region; the polar region shrinks as the magnetic field grows. Captured protons carry negative energy and angular momentum, whereas captured electrons carry positive energy and angular momentum. Fixing the capture domain by the gauge-invariant flux criterion and integrating over the \((r,θ)\) plane, we find that in weak magnetic fields the black hole gains mass, while in strong magnetic fields energy extraction occurs. Energy extraction can be achieved under the usual spherically symmetric density, without introducing the anisotropic density distribution required in the Wald solution for a Kerr black hole.
