Theoretical Description of kHz QPOs in accreting LMXB systems

We describe kHz QPOs from the hydrodynamical model of accretion disks for LMXB systems. Out of the pair, the higher frequency originates due to the viscous effects of an accretion disk involving the formation of shock, while the lower one is due to the Keplerian motion of accreting matter. Comparing our results with observations for two fast rotating compact stellar candidates, namely, 4U 1636-53 and KS 1731-260, we find that they match to a very good approximation.