Testing Universal Relations under Nonparametric Equations of State

Universal relations are proposed relationships between neutron star observables that are thought to hold regardless of the cold supranuclear equation of state. In this work, we use non-parametric equation of state models to test these relationships by implementing a measure of their goodness of fit as compared to astrophysical observability. Our model-agnostic approach allows us to more rigorously observe the equation of state independence present in these relations, by limiting the microscopic correlations due to nuclear modeling. We find relations between tidal deformability, moment of inertia, and the quadrupole moment are robust while other relations, such as between compactness and tidal deformability will require more analysis with third generation sensitivity.