标题： 裸奇点在广义引力理论中是否普遍存在？ 显示英文标题

标题： Do naked singularities generically occur in generalized theories of gravity?

摘要： 在有效超弦理论中发现了一种导致裸奇点的新机制。 我们研究了在纯宇宙常数“势”存在的情况下，球对称爱因斯坦-麦克斯韦-稀释子系统中的引力坍缩，该系统没有静态黑洞解。 我们证明一旦系统中发生引力坍缩，裸奇点必然出现，即场方程在外部通信区域中失效。 这表明在广义引力理论中，如果系统没有静态或稳态黑洞解，非最小耦合场在引力坍缩过程中通常会导致裸奇点。 显示英文摘要

摘要： A new mechanism for causing naked singularities is found in an effective superstring theory. We investigate the gravitational collapse in a spherically symmetric Einstein-Maxwell-dilaton system in the presence of a pure cosmological constant "potential", where the system has no static black hole solution. We show that once gravitational collapse occurs in the system, naked singularities necessarily appear in the sense that the field equations break down in the domain of outer communications. This suggests that in generalized theories of gravity, the non-minimally coupled fields generically cause naked singularities in the process of gravitational collapse if the system has no static or stationary black hole solution.