Abstract It has been shown by Banados, Silk and West (BSW) that the center of mass energy ( E cm ) of test particles starting from rest at infinity and colliding near the horizon of a Schwarzschild black hole is always finite. In this short note, we extent the BSW scenario and study two particles with different energies colliding near the horizon of a static spherically symmetric black hole. Interestingly, we find that even for the static spherically symmetric (i.e., Schwarzschild like) black holes it is possible to obtain an arbitrarily high E cm from the two test particles colliding near but outside of the horizon of a black hole, if one fine-tunes the parameters of geodesic motion.

中文翻译：

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静态球对称黑洞附近的粒子碰撞

摘要 Banados、Silk 和 West (BSW) 已经证明，从无穷远处静止开始并在 Schwarzschild 黑洞视界附近碰撞的测试粒子的质心能量 (E cm ) 总是有限的。在这篇简短的笔记中，我们扩展了 BSW 场景并研究了两个具有不同能量的粒子在静态球对称黑洞的视界附近碰撞。有趣的是，我们发现即使对于静态球对称（即类似 Schwarzschild 的黑洞），也有可能从两个测试粒子在黑洞视界附近但在黑洞视界外碰撞中获得任意高的 E cm ，如果一个细调整测地线运动的参数。