Gravitational wave in f(R) gravity: possible signature of sub- and super-Chandrasekhar limiting mass white dwarfs

TL;DR

This paper explores how gravitational wave observations could detect peculiar white dwarfs with unusual masses, providing a way to test f(R) gravity theories that explain these objects.

Contribution

It proposes a method to identify sub- and super-Chandrasekhar white dwarfs via gravitational wave signatures, linking modified gravity theories with observational prospects.

Findings

All relevant polarization modes' amplitudes estimated for different white dwarfs.

Detection prospects discussed for future gravitational wave detectors.

Potential to constrain or rule out f(R) gravity models based on observations.

Abstract

After the prediction of many sub- and super-Chandrasekhar (at least a dozen for the latter) limiting mass white dwarfs, hence apparently peculiar class of white dwarfs, from the observations of luminosity of type Ia supernovae, researchers have proposed various models to explain these two classes of white dwarfs separately. We earlier showed that these two peculiar classes of white dwarfs, along with the regular white dwarfs, can be explained by a single form of the f(R) gravity, whose effect is significant only in the high-density regime, and it almost vanishes in the low-density regime. However, since there is no direct detection of such white dwarfs, it is difficult to single out one specific theory from the zoo of modified theories of gravity. We discuss the possibility of direct detection of such white dwarfs in gravitational wave astronomy. It is well-known that in f(R) gravity, more than two polarization modes are present. We estimate the amplitudes of all the relevant modes for the peculiar as well as the regular white dwarfs. We further discuss the possibility of their detections through future-based gravitational wave detectors, such as LISA, ALIA, DECIGO, BBO, or Einstein Telescope, and thereby put constraints or rule out various modified theories of gravity. This exploration links the theory with possible observations through gravitational wave in f(R) gravity.