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arXiv · 1706.03596

Stellar equilibrium configurations of white dwarfs in the $f(R,T)$ gravity

G. A. Carvalho·R. V. Lobato·P. H. R. S. Moraes·José D. V. Arbañil·R. M. Marinho Jr·E. Otoniel·M. Malheiro
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Abstract

In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively. Considering the functional form $f(R,T)=R+2λT$, with $λ$ being a constant, we obtain the hydrostatic equilibrium equation for the theory. Some physical properties of white dwarfs, such as: mass, radius, pressure and energy density, as well as their dependence on the parameter $λ$ are derived. More massive and larger white dwarfs are found for negative values of $λ$ when it decreases. The equilibrium configurations predict a maximum mass limit for white dwarfs slightly above the Chandrasekhar limit, with larger radii and lower central densities when compared to standard gravity outcomes. The most important effect of $f(R,T)$ theory for massive white dwarfs is the increase of the radius in comparison with GR and also $f(R)$ results. By comparing our results with some observational data of massive white dwarfs we also find a lower limit for $λ$, namely, $λ>- 3\times 10^{-4}$.

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BibTeXRIS

G. A. Carvalho, R. V. Lobato, P. H. R. S. Moraes, José D. V. Arbañil, R. M. Marinho Jr, E. Otoniel, M. Malheiro. 2017-11-24. Stellar equilibrium configurations of white dwarfs in the $f(R,T)$ gravity. https://doi.org/10.1140/epjc%2Fs10052-017-5413-5

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