Speaker
Description
We investigate neutron star structure within the framework of Minimal Dilatonic Gravity (MDG), a scalar–tensor extension of gravity closely related to Brans–Dicke theory with ω=0. Employing two realistic unified equations of state (LOCV1811 and LOCV1815), we explore stellar configurations across different values of the dilaton mass mΦ. Our analysis reveals the emergence of a dilaton halo surrounding the neutron star, which contributes notably to the overall mass. For stars exceeding 2M⊙, the halo accounts for about 20–30% of the total mass, resulting in heavier objects than those predicted by General Relativity. These findings are in agreement with mass constraints derived from recent gravitational wave detections and NICER measurements. We further show that lighter dilaton masses produce more massive star–halo systems. At high densities, the dilaton pressure becomes negative in the stellar core, resembling dark energy behavior and altering the radial distribution of the field.
Keywords: Minimal Dilatonic Gravity, neutron stars, LOCV1811, LOCV1815, dilaton field, scalar–tensor theory, dilaton halo
