Slowly rotating neutron stars in the nonminimal derivative coupling sector of Horndeski gravity

Abstract

This work is devoted to the construction of slowly rotating neutron stars in the framework of the nonminimal derivative coupling sector of Horndeski theory. We match the large radius expansion of spherically symmetric solutions with cosmological solutions and we find that the most viable model has only one free parameter. Then, by using several tabulated and realistic equations of state, we establish numerically the upper bound for this parameter in order to construct neutron stars in the slow rotation approximation with the maximal mass observed today. We finally study the surface redshift and the inertia of these objects and compare them with known data.

Lovelock Galileons and black holes

“…A different way to bifurcate no hair theorems is to involve scalar tensor interactions involving translational invariant Galileons such as the John term of Fab 4 which reads, G µ ν ∇ µ φ∇ ν φ where G µν is the 4 dimensional Einstein tensor. There when one considers additionally a linear time dependence of the scalar field [27] (see also [28][29][30][31][32][33][34], and [35][36][37][38][39][40][41]) it was shown that the time dependence yielded analytic GR like black holes with additionally well defined scalars on the black hole horizon. For a recent review on black holes and scalar fields see [42] and [43].…”

Equilibrium and stability of relativistic stars in extended theories of gravity

“…Therefore, a promising route of investigation is firstly to set a specific model of dense matter, i.e., an equation of state, and then proceed computing macroscopic properties of neutron stars in a given ETG. Indeed, the predictions of alternative theories to GR concerning the structure of compact objects is currently an active research field [26][27][28][29][30][31][32].…”

Static and rotating solutions for vector-Galileon theories

“…In addition, solutions describing neutron stars and other compact objects have come out, imposing several constraints on the validity of these kinds of models [28][29][30][31]. These theories attracted a lot of interest also in the cosmology community as they might play a role in explaining inflation, dark energy, or dark matter [32].…”