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We numerically investigate black-hole and black-ring formation in five-dimensional space-time. We model the initial matter distribution in homogeneous spheroidal and toroidal configurations under the momentarily static assumption and express the matter with collisionless particles. Evolutions of space-time and particles are followed by using ADM formalism (4+1 decomposition) and solving the geodesic equation. For spheroidal configurations, we repeat the simulation performed by Shapiro and Teukolsky (1991) that announced an appearance of a naked singularity, and also find similar results in the 5D version. That is, in a collapse of a highly prolate spindle, the Kretschmann invariant blows up outside the matter and no apparent horizon forms. We also find that the collapses in 5D proceed more rapidly than in 4D, and the critical prolateness for the appearance of an apparent horizon in 5D is loosened, compared to 4D cases. We also show how collapses differ with spatial symmetries comparing 5D evolutions in single-axisymmetry, SO(3), and those in double-axisymmetry, $U(1)\times U(1)$ [2]. For toroidal configurations in $U(1)\times U(1)$ symmetry, we consider the rotating collisionless particles which consist of equal numbers co-rotating and counter-rotating under a certain rotational law. We also search both spherical($S^3$) and ring-shaped($S^2\times S^1$) horizons. We show topology change of apparent horizon from ring-shaped to spherical shape during its evolution [3]. Finally, we discuss the formation condition of apparent horizon in the context with the ``hyper-hoop" conjecture by evaluating closed two-dimensional submanifold of the horizon [1, 3]. [1] Y. Yamada and H. Shinkai, Class. Quant. Grav. {\bf 27}, 045012 (2010). [2] Y. Yamada and H. Shinkai, Phys. Rev. D {\bf 83}, 064006 (2011). [3] Y. Yamada and H. Shinkai, in preparation.

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