White dwarfs in de Rham-Gabadadze-Tolley like massive gravity

The existence of possible massive white dwarfs more than the Chandrasekhar limit ($1.45\text{ }{M}_{\ensuremath{\bigodot}}$, in which ${M}_{\ensuremath{\bigodot}}$ is mass of the sun) is a challenging topic. In this regard, and motivated by the important effect of massive graviton on the structure of white dwarfs, we study the white dwarfs in Vegh's massive gravity which is known as one of theories of de Rham, Gabadadze, and Tolley (dRGT) like massive gravity. First, we consider the modified Tolman-Oppenheimer-Volkoff equation in this theory of massive gravity and solve it numerically by using the Chandrasekhar's equation of state. Our results show that the maximum mass of white dwarfs in massive gravity can be more than the Chandrasekhar limit ($M>1.45\text{ }{M}_{\ensuremath{\bigodot}}$), and this result imposes some constraints on parameters of massive gravity. Then, we investigate the effects of various parameters on other properties of the white dwarfs such as mass-radius relation, mass-central density relation, Schwarzschild radius, average density, and Kretschmann scalar. Next, we study dynamical stability condition for super-Chandrasekhar white dwarfs and show that these massive compact objects enjoy dynamical stability. Finally, in order to have a better insight, we compare the super-Chandrasekhar white dwarfs with the obtained massive neutron stars in dRGT like massive theory of gravity.

Hali tarjima qilinmagan