Generalised Inverse-Cowling Approximation for Polar w-mode Oscillations of Neutron Stars
نویسنده
چکیده
Adopting the Lindblom-Detweiler formalism for polar oscillations of neutron stars, we study the w-mode oscillation and find that the Lagrangian change in pressure, measured by the physical quantity X , is negligibly small. Based on this observation, we develop the generalised inverse-Cowling approximation (GICA) with the approximation X = X ′ = 0, where X ′ is the derivative of X with respect to the circumferential radius, for w-mode oscillations of neutron stars. Under GICA, w-mode oscillations are described by a second-order differential system, which can yield accurate frequencies and damping rates of quasi-normal modes.
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