Fast rotation of strange stars

Exact models of uniformly rotating strange stars, built of selfbound quark matter, are calculated within the framework of general relativity. This is made possible thanks to a new numerical technique capable of handling the s trong density discontinuity at the surface of these stars. Numerical calcul ations are done for a simple MIT bag model equation of state of strange qua rk matter. Evolutionary sequences of models of rotating strange stars at co nstant baryon mass are calculated. Maximally rotating configurations of str ange stars are determined, assuming that the rotation frequency is limited by the mass shedding and the secular instability with respect to axisymmetr ic perturbarions. Exact formulae which give the dependence of the maximum r otation frequency, and of the maximum mass and corresponding radius of rota ting configurations, on the value of the bag constant, are obtained. The va lues of T/W for rapidly rotating massive strange stars are significantly hi gher than those for ordinary neutron stars. This might indicate particular susceptibility of rapidly rotating strange stars to triaxial instabilities.