Dynamical stability of strange quark stars

TL;DR

This paper demonstrates that models of pure strange quark stars do not satisfy the conditions for hydrostatic stability within General Relativity, challenging claims that certain observed compact objects could be strange stars.

Contribution

It shows that the mass-radius relations for strange quark matter models do not meet the necessary stability conditions, questioning the existence of pure strange quark stars in equilibrium.

Findings

Models do not fulfill hydrostatic equilibrium conditions.

Pure strange quark stars cannot exist in stable equilibrium.

Implications for identifying observed objects as strange stars.

Abstract

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 Day et al (1998) do not provide the necessary and sufficient condition for dynamical stability for the equilibrium configurations, since such configurations can not even fulfill the necessary condition of hydrostatic equilibrium provided by the exterior Schwarzschild solution. These findings will remain unaltered and can be extended to any other sequence of pure SQM. This study explicitly show that although the strange quark matter might exist in the state of zero pressure and temperature, but the models of pure strange quark `stars' can not exist in the state of hydrostatic equilibrium on the basis of General Relativity Theory. This study can affect the results which are claiming that various objects like - RX J1856.5-3754, SAX J1808.4-3658, 4U 1728-34, PSR 0943+10 etc. might be strange stars.