DYNAMICAL STABILITY OF STRANGE QUARK STARS

Abstract

The necessary and sufficient condition for dynamical stability is worked out for the sequences of relativistic star models which correspond to the well-defined and causal values of adiabatic sound speed, [Formula: see text], at the center. On the basis of the conditions obtained in this study, we show that the mass–radius (M-R) relation corresponding to the MIT bag models of strange quark matter (SQM) and the models obtained by Dey et al. [Phys. Lett. B438 (1998) 123] does not provide the necessary and sufficient condition for dynamical stability for the equilibrium configurations. These findings will remain unaltered and can be extended to any other sequence of pure SQM. This study explicitly shows that though SQM may exist in the state of zero pressure and temperature, the models of pure strange quark "stars" cannot exist in the state of hydrostatic equilibrium. This study can affect the results which are claiming that various objects, like RX J1856.5-3754, SAX J1808.4-3658, 4U 1728-34 and PSR 0943+10, represent strange stars.