Dynamics of gravitating magnetic monopoles.

According to previous work on magnetic monopoles, static regular solutions are nonexistent if the vacuum expectation value of the Higgs eld is larger than a critical value cr, which is of the order of the Planck mass. In order to understand the properties of monopoles for > cr, we investigate their dynamics numerically and classify those dynamical solutions into three types as follows. If is larger than another critical value inf (> cr), a monopole in ates and a wormhole structure appears around it. In the case of cr < < inf, in ation does not occur and the dynamics depend on the ratio of the Higgs self coupling constant and the gauge coupling constant e: if =e < 1, a monopole just shrinks and becomes a black hole; otherwise, a monopole approaches a stable con guration. Electronic address: sakai@c .waseda.ac.jp