Stability criterion for white dwarfs in Palatini f(R) gravity

Recent observations of several peculiar over- and underluminous type Ia supernovae infer indirect evidence for the violation of the Chandrasekhar mass limit by suggesting the existence of super- and sub-Chandrasekhar limiting mass white dwarfs. In an attempt to explain these phenomena in the context of general relativistic extensions, we study these objects in Palatini f(R) gravity. We obtain the super- and sub-Chandrasekhar limiting masses as well as the dynamical instability criteria for white dwarfs in the given gravitational theory. We further demonstrate that the conventional positivity condition partial derivative M/partial derivative(rho c) > 0 with M being the WD's mass with central density rho(c) is also a valid criterion for stability in Palatini gravity.

Automated summary

Recent observations suggest the violation of Chandrasekhar mass limit in supernovae and the existence of white dwarfs with super- and sub-Chandrasekhar limiting masses. In this study, we investigate these objects using Palatini f(R) gravity in the context of general relativistic extensions. We determine the limiting masses and dynamical instability criteria for white dwarfs in this gravitational theory. Furthermore, we demonstrate that the conventional positivity condition remains valid for stability in Palatini gravity.