Universal Inflationary Attractors Implications on Static Neutron Stars

Abstract: We study static neutron stars in the context of a class of non-minimally coupled inflationary potentials, the universal attractors. Universal attractors are known to generate a viable inflationary era, and they fall into the same category of inflationary phenomenology as the $R^2$ model and other well-known cosmological attractors. We present the essential features of universal attractors in both the Einstein and Jordan frame, and we extract the Tolman-Oppenheimer-Volkoff equations in the Einstein frame using the usual notation of theoretical astrophysics. We use a python 3 based double shooting numerical code for our numerical analysis and we construct the $M-R$ graphs for the universal attractor potential, using piecewise polytropic equation of state the small density part of which is the WFF1 or the APR or the SLy equation of state. As we show, all the studied cases predict larger maximum masses for the neutron stars, and all the results are compatible with the GW170817 constraints imposed on the radii of the neutron stars.