Breaking bad degeneracies with Love relations: Improving gravitational-wave measurements through universal relations

The distance-inclination degeneracy limits gravitational-wave parameter estimation of compact binary mergers. Although the can be partially broken by including higher-order modes or precession, these effects are suppressed in neutron stars. In this work, we implement a new parametrization tidal neutron-star waveform, exploiting Love relations, that breaks degeneracy. relations prescribe deformability star as function its source-frame mass an equation-of-state insensitive way and, thus, allows direct measurement redshift source. If cosmological parameters assumed to known, converted luminosity distance, and thus broken. We approach, studying range observing scenarios using Bayesian on synthetic data. era third-generation detectors, for observations with signal-to-noise ratios ranging from 6 167, forecast up $\sim70\%$ decrease $90\%$ credible interval distance inclination $\sim50\%$ component masses. For edge-on systems, our approach result moderate ($\sim50\%$) improvement measurements binaries ratio low 10. This prescription used better infer masses hence, refine population properties stars, such their maximum mass, impacting nuclear astrophysics. When combined search electromagnetic counterpart observations, work presented here put improved bounds opening angle jets