Horizons of coalescing black holes on the Eguchi-Hanson space

Using the numerical method, we study the dynamics of coalescing black holes on the Eguchi-Hanson base space. The effects of a difference in spacetime topology on the black hole dynamics is discussed. We analyze the appearance and disappearance process of marginal surfaces. In our calculation, the area of a coverall black hole horizon at the creation time in the coalescing black hole solutions on the Eguchi-Hanson space is larger than that in the five-dimensional Kastor-Traschen solutions. This fact suggests that the black hole production on the Eguchi-Hanson space is easier than that on the flat space