标题： 关于单一点电荷的静态时空 显示英文标题

标题： On the Static Spacetime of a Single Point Charge

摘要： 在所有满足以下条件的电磁理论中：(a) 可从拉格朗日量导出，(b) 满足主导能量条件，以及 (c) 在弱场极限下与经典线性电动力学一致，我们确定了某一子类，其对应的静态、球对称、渐近平直的静电真空时空度规在其中心具有最轻微的奇异性，即时间轴上的锥状奇异性。此外，电场在时间轴上有一个点缺陷，其总能量有限，并且等于时空的ADM质量。通过适当缩放拉格朗日量，可以调整这些时空的总质量和总电荷为任意选定值。对于足够小的质量-电荷比，这些时空没有视界且没有被困的零测地线。我们证明了这些解在球对称类中的唯一性。最后，我们对这些时空的测地线和试探电荷轨迹进行了定性研究。 显示英文摘要

摘要： Among all electromagnetic theories which (a) are derivable from a Lagrangian, (b) satisfy the dominant energy condition, and (c) in the weak field limit coincide with classical linear electromagnetics, we identify a certain subclass with the property that the corresponding static, spherically symmetric, asymptotically flat electrovacuum spacetime metric has the mildest possible singularity at its center, namely, a conical singularity on the time axis. The electric field moreover has a point defect on the time axis, its total energy is finite, and is equal to the ADM mass of the spacetime. By an appropriate scaling of the Lagrangian, one can arrange the total mass and total charge of these spacetimes to have any chosen values. For small enough mass-to-charge ratio, these spacetimes have no horizons and no trapped null geodesics. We prove the uniqueness of these solutions in the spherically symmetric class. We conclude by performing a qualitative study of the geodesics and test-charge trajectories of these spacetimes.