Gravitational Wave Propagation in K-essence Cosmology: Theory and Observational Constraints
This study investigates gravitational wave (GW) propagation in kessence cosmology, where dark energy is described by a non-canonical scalar field. It shows that this background field induces a time-dependent effective mass term ($m_{ ext{eff}}$) for GWs, modifying their dispersion relation without changing the speed of light. Joint analysis of cosmic chronometers and gravitational wave data constrains this effect to an ultra-light physical scale around $10^{-33}$ eV, offering a mechanism to potentially resolve the Hubble tension.