The no-hair theorem of general relativity states that isolated black holes are characterized by three parameters: mass, spin, and charge. In this Letter we consider Kerr black holes endowed with highly magnetized plasma-filled magnetospheres. Using general relativistic kinetic plasma and resistive magnetohydrodynamics simulations, we show that a dipole magnetic field on the event horizon opens into a split monopole and reconnects in a plasmoid-unstable current sheet. The no-hair theorem is satisfied, in the sense that all components of the stress-energy tensor decay exponentially in time. We measure the decay time of magnetic flux on the event horizon for plasmoid-dominated reconnection in collisionless and collisional plasma. The reconnecting magnetosphere should be a powerful source of hard x-ray emission when the magnetic field is strong.

中文翻译：

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黑洞磁层中的磁毛和重联

广义相对论的无毛定理指出，孤立的黑洞具有三个参数：质量、自旋和电荷。在这封信中，我们考虑了具有高度磁化等离子体填充磁层的克尔黑洞。使用一般的相对论动力学等离子体和电阻磁流体动力学模拟，我们表明事件视界上的偶极子磁场打开成分裂的单极子，并在等离子体不稳定电流片中重新连接。满足无毛定理，即应力-能量张量的所有分量随时间呈指数衰减。我们测量了事件视界上磁通量的衰减时间，以便在无碰撞和碰撞等离子体中以等离子体团为主的重新连接。当磁场很强时，重新连接的磁层应该是一个强大的硬 X 射线发射源。