Speaker
Description
We study the structure of neutron stars within the framework of Minimal
Dilatonic Gravity (MDG), a scalar–tensor theory related to Brans–
Dicke gravity with ω = 0. Using two realistic unified equations of state
(EOS), LOCV1811 and LOCV1815, we analyze stellar configurations for
different values of the dilaton field mass mΦ. Our results show that a
dilaton halo forms around the neutron star, contributing significantly to
the total mass. The halo mass fraction reaches 20–30% in neutron stars
with masses greater than 2M⊙, leading to total masses that exceed those
predicted by General Relativity. These results are consistent with mass
measurements from recent gravitational wave and NICER observations.
We also find that smaller dilaton field masses yield more massive neutron
star–halo systems. For high-density stars, the dilaton pressure becomes
negative at the center and behaves like dark energy, modifying the radial
profile of the dilaton field.
Keywords: Minimal Dilatonic Gravity, neutron stars, LOCV1811, LOCV1815,
dilaton field, scalar-tensor theory, dilaton halo
